JP3182252U - Mechanical property measurement test equipment - Google Patents

Abstract

A mechanical property measuring and testing apparatus capable of measuring a mechanical property value of a material over a temperature range from a low temperature to a high temperature.
A transparent indenter 13 press-fitted into a test sample, an optical means 17 for observing the surface of the indenter 13 in contact with the sample through the indenter 13, a load loading means for press-fitting the indenter 13 into the sample, A load measuring means for measuring a load to be press-fitted, an image photographing means for photographing an image of a contact surface of the indenter 13 on the sample surface, and an image recording / analyzing means. The indenter 13 is a horizontal and transparent indenter holding plate. The optical means 17 is disposed above the indenter holding plate 14 so that the contact surface of the indenter 13 with the sample can be observed through the indenter holding plate 14 and the sample is heated. -By providing a constant temperature device 19 for holding in a cooled state and optically continuously measuring the contact area with the sample into which the indenter 13 is pressed, the mechanical property value of the sample in the heated / cooled state Measurement was possible.
[Selection] Figure 1

Description

  The present invention relates to a mechanical property measuring and testing apparatus. More specifically, the mechanical properties of materials such as hardness, Young's modulus, yield stress, creep compliance, and relaxation elastic modulus are set in a temperature range from a low temperature to a high temperature. The present invention relates to a mechanical property measurement test apparatus for cross-sectional measurement.

  Instrumented indentation is a type of test method for evaluating mechanical properties, and is measured by combining the load applied when a micro indenter is pushed into the surface of the object to be measured, the contact area, and the shape and characteristics of the indenter. It evaluates various mechanical properties of the object.

  In instrumentation indentation, an analysis method is generally used in which the indenter indentation depth is measured and the contact area is converted from the measured value, and the device uses a macro indenter according to the measurement resolution and measurement range. Various devices called micro indenters, nano indenters, pico coin denters, etc. are on the market.

  In recent years, these various indenters have been utilized in a wide range of industrial research fields and are making rapid progress. The reason for this is that miniaturized mechanical parts to which conventional macroscopic material testing methods cannot be applied, and functional thin films / thick films and films formed on substrates have begun to be put into widespread use. The background is that it has started to be recognized as the most suitable test method for evaluating the mechanical properties of these new materials.

  If the behavior of the surface deformation when the indenter is pushed into the surface of the test sample deviates significantly from the surface deformation behavior estimated by a completely elastic body due to the plasticity and viscoelastic properties of the test sample, There has been a problem that the calculated value of the contact area converted from the indentation depth of the indenter contains a large error, and as a result, the estimated value of the mechanical property is inaccurate.

  One type of instrumented indentation that can solve this problem is a test method called microindentation (Patent Document 1). This microindentation is a test method having a measurement principle different from that of general instrumented indentation. In contrast to conventional instrumented indentation, the contact area was converted from the indentation depth, while microindentation uses the optical properties of an indenter that is transparent to visible light. This is a test method that directly optically measures the contact surface. For this reason, in microindentation, the contact area can be accurately measured regardless of the plasticity or viscoelasticity of the sample to be examined, and the mechanical properties can be evaluated with high accuracy.

  Since microindentation has such excellent features, in addition to Young's modulus, hardness, yield stress, work hardening index, plastic deformation scale, etc., which are non-time-dependent properties of elasticity, elastoplasticity, and plasticity, Rheological properties such as creep compliance and relaxation modulus, which are time-dependent properties of viscoelastic properties, can also be evaluated (Patent Document 1, Non-Patent Document 1, Non-Patent Document 2).

  In order to perform a viscoelasticity test (rheological test) at any temperature from low to high temperature by microindentation, it is a device that can hold a test sample in a constant temperature state for an arbitrary time. It is necessary to drive only a minute amount so as to make contact, optically observe the contact behavior between the indenter and the sample surface using the visible light transparency of the indenter, and measure the load load with high accuracy. However, the test apparatus described in Patent Document 1 does not have a function that can maintain a test sample in a constant temperature state for an arbitrary time.

  An arrangement in which a heating element or a cooling body, a sample, and an indenter are connected in series is a method for simultaneously holding an absolute value measurement of the load and securing an optical path for optical measurement, and cooling or heating the test sample to a low or high temperature. (Non-Patent Document 1, Non-Patent Document 2). In that case, a power supply cable for transmitting energy to the heating element or the cooling body, a circulating hose for cooling water, and the like are mounted on the load measuring instrument.

  However, for a dynamic system in which the load measuring means, heating / cooling means, sample specimen, and indenter are connected in series, the power supply cable, thermocouple, cooling circulation water tube, etc. to the heating / cooling means arranged in parallel Wiring and piping also act as elastic springs. These are serious error factors that cannot be ignored in load measurement, and at the same time reduce the accuracy of the load measurement means. That is, since the load supported by the parallel spring is not transmitted to the load measuring means, the value measured by the load measuring means is always a low load load value obtained by subtracting the load supported by the spring from the net load load. turn into. The error due to the elastic spring effect depends on the material constituting the spring, the thickness, the quantity, and the installation angle. In addition, since the elastic property (elastic coefficient) fluctuates due to temperature changes in the chamber, it is technically very difficult to remove the elastic spring effect by means such as correction.

  An environmental test apparatus capable of optically observing a test sample placed inside a thermostat by combining an optical function with the thermostat has been developed (Patent Document 2). However, this test apparatus does not have a driving mechanism or a mechanical function related to load measurement necessary as a sample heating apparatus for a micro indenter.

  As a means for setting the test sample inside the thermostat to a constant temperature, a thermostat of a system in which warm air or cold air is sent to the vicinity of the sample or a system in which the air is refluxed has been proposed (Patent Document 3 and Patent Document 4). . However, in this thermostatic chamber, the fluctuation of warm air or cold air vibrates the sample and hinders detection of a minute load. Therefore, it is impossible to measure a load with high accuracy. For these reasons, there is a strong demand in this technical field to develop a mechanical property measurement test apparatus for measuring the mechanical properties of a test sample over a temperature range from a low temperature to a high temperature. It was.

Japanese Patent No. 4317743 Japanese Patent Laid-Open No. 8-152397 Japanese Patent No. 3608241 Japanese Utility Model Publication No. 6-45243

Norio Hagiri “Development of Mechanical Properties Evaluation Method by Microindentation”, Toyohashi University of Technology Graduate Thesis (2010) Motoji Sakai, “Construction of viscoelastic indenter mechanics and rheological measurement in the micro domain”, Journal of the Japan Rheological Society, Vol. 39, No. 1-2, Section 7-15 (2011) M.M. Sakai, S .; Kawaguchi, and N.K. Hakiri, J. et al. Mater. Res. , Vol. 27, no. 1, pp. 256-265 (2012)

  The present invention has been developed in view of the above-mentioned problems of the prior art, and enables continuous observation of the indentation state of the indenter into the test piece of the test sample in a heated / cooled state with high accuracy. To evaluate the various physical properties of the specimen with high accuracy from the quantitative relationship with the contact area measured by the method of moving image analysis from the optical image at the same time It is an object of the present invention to provide a new mechanical property measuring and testing apparatus that enables the above.

The present invention for solving the above problems comprises the following means.
(1) A transparent indenter that is press-fitted into the test sample, an optical means for observing the surface of the indenter in contact with the sample through the indenter, a load-loading means for press-fitting the indenter into the sample, and a load to be pressed are measured A mechanical property measurement test apparatus comprising: a load measuring unit; an image capturing unit that captures an image of a contact surface of an indenter on a sample surface; and an image recording / analyzing unit.
An indenter is attached to the lower surface of a horizontal and transparent indenter holding plate, and the optical means is arranged above the indenter holding plate so that the contact surface of the indenter with the sample can be observed through the indenter holding plate. In addition, a thermostatic device for holding the sample in a heated / cooled state is arranged, and the contact area with the sample into which the indenter is press-fitted is optically continuously measured. A mechanical property measurement tester characterized by enabling measurement of physical properties.
(2) The sample holder holding the sample, the heating / cooling means of the thermostatic device, and the load applying means are placed on the base plate of the internal frame, and the indenter holding plate to which the indenter is attached is The weight of the heating / cooling means and load loading means, and the elasticity of the power supply cable, circulating water hose and thermocouple connected to these means, The mechanical property measuring test apparatus according to (1), wherein the load measuring means is avoided and the press-fitting load of the indenter is measured.
(3) The mechanical property measurement test apparatus according to (2), wherein the load measurement resolution is 0.01 mgf or more.
(4) The mechanical property measurement test apparatus according to (2) or (3), wherein the sample holder is brought into contact with a heating / cooling unit to heat / cool the sample.
(5) The mechanical property measurement test apparatus according to any one of (2) to (4), wherein the heating / cooling means is a Peltier element.
(6) The mechanical property measuring and testing apparatus according to any one of (2) to (5), wherein the lower part of the optical means is covered with a chamber filled with a dry gas to prevent the occurrence of condensation and icing.
(7) The observation window is provided on the ceiling surface of the chamber between the optical means and the indenter holding plate so that the contact surface of the indenter with the sample can be observed by the optical means. Mechanical property test equipment.
(8) The sample holder is provided with a recess shallower than the sum of the height of the indenter and the sample thickness, and the sample is placed in this recess so that the sample holder and the indenter holding plate are spatially close to each other, The mechanical property measurement test apparatus according to any one of (2) to (7), wherein the constant temperature holding temperature of the sample, the sample holder, the indenter, and the indenter holding plate is made uniform.
(9) The mechanical property measuring and testing apparatus according to any one of (2) to (8), wherein an indenter held on an indenter holding plate is supported via a heat insulating material to block heat from entering and exiting.

Next, the present invention will be described in more detail.
A mechanical property measuring and testing apparatus according to the present invention includes a transparent indenter that is press-fitted into a test sample, an optical means for observing the surface of the indenter in contact with the sample through the indenter, and a load loading means that presses the indenter into the sample. And a load measuring means for measuring the press-fitting load, an image photographing means for photographing an image of the contact surface of the indenter on the sample surface, and an image recording / analyzing means.

  In the present invention, the indenter is attached to the lower surface of a horizontal and transparent indenter holding plate, the optical means is disposed above the indenter holding plate, and the contact surface of the indenter with the sample is interposed via the indenter holding plate. And a constant temperature device for holding the sample in a heated / cooled state, and by continuously observing the contact surface with the sample into which the indenter is press-fitted in an optically heated / cooled state. It is possible to measure the mechanical properties of samples in

  In the present invention, a sample holder holding a sample, heating / cooling means of a constant temperature device, and the load loading means are placed on a base plate of an internal frame, and an indenter holding plate to which an indenter is attached Is supported on a stand that is separated from the base plate, and the weight of the heating / cooling means and the load-loading means, and the feeding cable, circulating water hose, and thermocouple are connected to these means. It is desirable to measure the press-fit load of the indenter with high accuracy by avoiding the force from being applied to the load measuring means.

  In the present invention, the load measurement resolution can be set to 0.01 mgf or more, and heating / cooling means is brought into contact with the sample holder so that the sample is heated / cooled with high accuracy and speed. Moreover, a Peltier element, a ceramic heater, etc. can be used as a heating / cooling means.

  In the present invention, the bottom of the optical means can be covered with a chamber filled with dry gas to prevent the formation of condensation and icing, and the ceiling surface of the chamber between the optical means and the indenter holding plate can be prevented. In addition, an observation transparent plate or the like can be provided as an observation window so that the contact surface between the indenter and the sample can be observed by optical means.

  The sample holder is provided with a recess shallower than the sum of the height of the indenter and the sample thickness, and the sample is placed in this recess so that the sample holder and the indenter holding plate are spatially close to each other. The constant temperature holding temperature of the holder, the indenter, and the indenter holding plate can be made uniform, and the indenter holding plate can be fixed via a heat insulating material to block heat from entering and leaving.

  In the present invention, the sample holder holding the sample, the heating / cooling means of the thermostatic device, and the load loading means are placed on the platform. In addition, the indenter holding plate to which the indenter is attached is supported by a support column that is erected separately from the base plate. Accordingly, the weight of the heating / cooling means and the load loading means, and the elastic force of the power supply cable, circulating water hose, and thermocouple connected to these means are avoided from being applied to the load measuring means. It is possible to measure the press-fit load.

  In the present invention, an appropriate shape, structure and type of transparent indenter can be used. As the optical means, any means can be used as long as it can observe the surface of the indenter in contact with the sample through the indenter.

  As load load means for press-fitting the indenter into the sample and load measurement means for measuring the load to be press-fitted, any appropriate means can be used as long as it has these functions. As the image photographing means and the image recording / analyzing means, any means can be used as long as it can photograph, record and analyze the image of the contact surface of the indenter on the sample surface.

  As for the indenter holding plate, as long as the illumination optical path and the contact surface observation optical path are transparent, other portions may be opaque and an appropriate material can be used. In addition, as a method for fixing the indenter to the indenter holding plate, an appropriate adhesive can be used as long as the measurement test temperature is within the corresponding range of the adhesive. The adhesive may be made of a material that becomes opaque after curing as long as the indenter can be fixed by securing the illumination optical path and the contact surface observation optical path. Of course, if an adhesive that is transparent and has high rigidity after curing is selected, the area between the indenter and the indenter holding plate can be used as an adhesion location. In low and high temperature ranges that exceed the range of use of adhesives, fixing methods using mechanical means such as screwing set bolts and cap nuts, and integrated molding that cuts the indenter holding plate and indenter from the same member It can be selected as appropriate from the law. As the thermostat, any appropriate means can be used as long as it is a means for holding the sample in a heated / cooled state.

  In the mechanical property measuring and testing apparatus of the present invention, an indenter 13 and an indenter holding plate 14 to which the indenter is attached are supported by a heat insulating support 11 and supported by a Z-axis stage via a load cell type electronic balance 30. . On the other hand, the sample holder 2 holding the sample 1, the heating / cooling means 19 of the thermostatic device, and the Z-axis piezo actuator 25 which is a load-loading means are placed on the base plate 33 of the internal frame 32.

  In FIG. 1, 1 is a sample sample, 2 is a sample holder, 3 is a chamber, 4 is an observation window, 5 is a hermetic connector, 6 is an inlet for dry gas, 7 is an outlet for dry gas, 8 is an inlet for cooling circulating water, 9 is an outlet for cooling circulating water, 10 is a tube for cooling circulating water, 11 is a heat insulating support, 12 is illumination, 13 is a transparent indenter such as diamond or sapphire, 14 is an indenter holding plate for holding the indenter, 15 Is an objective lens for an optical microscope, 16 is an actuator for finely moving the objective lens to correct optical focus shift, 17 is an optical microscope, 18 is a heater for preventing fogging of the observation window, 19 is a Peltier element, ceramic heater, etc. Heating / cooling means 20, 20 is a power supply cable for heating / cooling means, 21 is a power supply cable for piezo actuator, 22 to 24 and 35 are X to Z steps. Signal cable, 25 to 28 are X to Z stages, 29 is a Z-axis coarse movement stage for exchanging samples, 30 is a load cell type electronic balance, 31 is a signal cable for the load cell type electronic balance, and 32 is an internal frame , 33 is a base of the internal frame, and 34 is a thermocouple.

  In the display of FIG. 1, only the part related to the load is displayed by hatching, and the distinction from the part not related to the load measurement is made clear. Furthermore, the load cell type electronic balance 30 has a communication function (communication interface such as RS232C) with an external computer (computer), and the data transfer rate through the interface is 92 per second at the maximum. Therefore, the load value measured by the load cell type electronic balance can be sequentially acquired at the same speed as the analog load cell.

  These means can be replaced by other means having the same effect as necessary, and some of the means can be omitted as appropriate within the scope of the present invention.

  Procedures and evaluation formulas for calculating various mechanical properties simply and precisely are shown below (Non-patent Documents 2 and 3). The evaluation formulas for calculating various mechanical characteristic values can be selected from different evaluation formulas, and are not limited.

First, the evaluation method of Mayer hardness H _M of the hardness H, which is known as elastic-plastic parameters. Meyer hardness H _M is indenter its tip is an acute angle, for example, in contact with, such as a triangular pyramid indenter and a quadrangular pyramid indenter, cone indenter is defined as divided by the projected contact area A of the applied load P . If Indentation site of sample specimen is said to be homogeneous of homogeneous properties, the value of Meyer hardness H _M tip is evaluated by a test using the indenter is an acute angle does not depend on the applied load. Accordingly, Meyer hardness H _M from actually measuring a set of measured values of any applied load P and the contact area A in synchronization with the time axis can be calculated from the following equation.

Furthermore, in order to improve the calculation accuracy of Mayer hardness H _M is the applied load P to the Y axis, the contact area A the relation between the applied load P and the contact area A, plotted on the X axis (P-A relation) draw a graph may be calculated Meier hardness H _M the initial linear as the slope approximated by a least square method.

  Next, a method for evaluating the Young's modulus E ′, which is an elastic parameter, will be described. The Young's modulus E ′ is evaluated by using a set of continuously measured values of the load P and the contact area A synchronized with the time axis in the process of unloading the contact using an indenter whose tip is acute. it can. That is, if the gradient M estimated by approximating the straight line immediately after the start of unloading in the graph of the relationship between the load P and the contact area A (PA relationship) by the least square method is substituted into the following equation, the Young's modulus E 'Can be calculated. Here, β is the surface inclination angle of the used indenter, which is 24.97 ° for the triangular pyramid indenter (Berkovich type) and 22.0 ° for the quadrangular pyramid indenter (Vickers type).

The Young's modulus E ′ can also be evaluated from a contact loading process using an indenter whose tip is spherical (tip radius of curvature: R). First, a graph plotting the relationship between the load P and the contact circle radius a ³ (P−a ³ relationship) using a set of continuous measurement values of the load P and the contact circle radius a synchronized on the time axis. Create Then, the Young's modulus E ^* can be calculated by approximating the load straight line by the least square method or the like to estimate the slope (gradient) k of the straight line and substituting the value into the following equation.

Here, R is the radius of curvature of the spherical indenter used in the test. The Young's modulus E ^* obtained by this equation is a composite Young's modulus of the Young's modulus E ′ of the sample sample and the Young's modulus E _{i of the} material constituting the indenter. Can be converted.

Next, an evaluation method of the yield stress Y that is a plastic parameter will be described. Yield stress Y is defined as the point of departure from the linear relationship at the initial stage of load in the stress-strain curve. Here, the stress in the indentation test has an average contact pressure p _m, also, distortion is defined a contact circle radius a as a value obtained by dividing the radius of curvature R of the spherical indenter. Therefore, as in the case of the Young's modulus test, in a contact test using an indenter whose tip is spherical, a set of continuous measurement values of the load P and the contact circle radius a synchronized on the time axis is obtained. If measured, a stress-strain curve expressed by the following equation can be obtained as a graph.

  Under the condition that the load applied for contact is low, the contact occurs within the elastic range, and the stress-strain curve exhibits a constant value based on the Young's modulus in the initial load of the stress-strain curve, so that the stress-strain curve shows a linear relationship. Further, the deviation from the straight line indicating the linear relationship clearly indicates that the transition to the behavior governing elasto-plastic deformation has occurred. Therefore, the yield stress Y is obtained as a point deviating from the linear relationship at the initial stage of load in the stress-strain curve graph.

  As a second method for evaluating the yield stress Y, a method using an indenter whose tip is an acute angle will be described. Since the yield stress Y is a plastic property, it can be obtained as a difference between the elastic-plastic property and the elastic property. That is, since the elasto-plastic characteristics and elastic characteristics are already measured by the above-described method using the test apparatus of the present invention, the yield stress Y, which is a plastic characteristic, can be calculated by the following equation.

Here, the coefficient C is a constant and is known to take a value of 2.65. Furthermore, the coefficient f is dynamic interactors of elastic deformation and plastic deformation, when the ratio A _{p /} A _e of the elastic contact area A _e and plastic contact area A _p to measure x of plastic deformation, the following equation It is expressed by

  Next, an evaluation method for describing the mechanical properties of a polymer material, plastics, a metal having a low melting point, etc. exhibiting time-dependent deformation behavior as a rheological function will be described. First, it is a relaxation elastic modulus E '(t) known as a typical rheological function. The relaxation elastic modulus E ′ (t) is a function of temperature and time. In the apparatus of the present invention, the sample area is held at a predetermined temperature by heating / cooling means, and the contact area is set to a constant value A. Thus, it can be determined by measuring the behavior that the load relaxes over time.

  First, as a drive control of the device of the present invention, a drive mechanism such as a piezo actuator is operated as fast as possible, and the speed of the drive mechanism is adjusted as soon as possible after reaching a predetermined contact area without excess or deficiency. The position control mode of the drive mechanism is changed to constant area holding control so that the area value maintains a constant value A. That is, in the plot of the relationship between the contact area A and time t, the drive mechanism is controlled so that the contact area is stepped (stepped).

  On the other hand, as the measurement of the device of the present invention, the time for the contact area to rise stepwise is defined as zero, and the load change (load relaxation) P (t) is continuously measured. The relaxation elastic modulus E ′ (t) is calculated by the following equation.

Here, _Ave is a viscoelastic contact area obtained by removing a plastic component from the contact area, and is represented by the following equation.

  Here, the coefficient C is a constant having a value of 2.65, and Y is a yield stress obtained from the expressions (6) and (7). If the device of the present invention is not used, a relaxation test under a constant contact area condition cannot be realized.

Further, a method for evaluating a creep compliance D ′ (t), which is a representative rheological function, by a constant load creep test will be described. Creep compliance D ′ (t) is a function of temperature and time. In the apparatus of the present invention, the sample specimen is held at a predetermined temperature by heating / cooling means, and the load is set to a constant value P _0. Thus, it can be determined by measuring the behavior in which the contact area A (t) increases with the passage of time.

First, the drive control device of this paper proposed to operate as fast as possible the driving mechanism such as a piezoelectric actuator, by adjusting the speed of as soon as possible driving mechanisms when it reaches just proportion to a predetermined applied load P _0, as applied load value changes the position control mode of the drive mechanism so as to maintain a constant value P ₀ the constant load holding control. That is, in the plot of the relationship between the load load P ₀ and time t, the drive mechanism is controlled so that the load load is stepped (stepped).

  On the other hand, on the measurement side of the device of the present invention, the time for the load to rise in a staircase pattern is defined as zero, and the contact area increase A (t) is continuously measured. The creep compliance D ′ (t) is calculated by the following equation.

Here, A _ve (t) is a viscoelastic contact area obtained by removing the plastic component from the increase A (t) of the contact area, and is expressed by the following equation.

  Here, the coefficient C is a constant having a value of 2.65, and Y is a yield stress obtained from the expressions (6) and (7).

  The creep compliance D ′ (t) can also be evaluated by a constant speed load test. The creep compliance D ′ (t) is a function of temperature and time. In the apparatus of the present invention, the sample specimen is held at a predetermined temperature by the heating / cooling means, and the load speed becomes a constant value V. It can be determined by measuring the time-varying behavior of the contact area while controlling the load type.

First, as drive control of the device of the present invention, the drive mechanism of the drive mechanism such as a piezo actuator is adjusted so that the increment (load speed) per unit time of the load load is kept constant V. That is, the drive mechanism is controlled so that the plot indicating the relationship between the load P ₀ and the time t is linear (P = Vt).

  On the other hand, on the measurement side of the apparatus of the present draft, the time when the load load starts to increase linearly is defined as zero, and the contact area increase A (t) is continuously measured. The creep compliance D ′ (t) is calculated by the following equation.

Here, dA _ve / dt is a viscoelastic contact area obtained by removing a plastic component from the increase A (t) of the contact area, and is expressed by the following equation.

  Here, the coefficient C is a constant having a value of 2.65, and Y is a yield stress obtained from the expressions (6) and (7).

The mechanical effect measuring and testing apparatus according to the present invention has the following effects.
(1) The indenter and the indenter holding plate are made of a transparent material, and the optical means is arranged above the indenter holding plate so that the contact surface of the indenter with the sample can be visually recognized through the indenter holding plate. Therefore, it is possible to continuously observe the indentation state of the indenter into the test piece of the test sample.
(2) Furthermore, since a thermostat is provided, the mechanical property value of the sample held in a heated / cooled state can be measured.

(3) Further, in the mechanical property measurement test apparatus according to the present invention, the sample holder, the heating / cooling means of the thermostatic apparatus, and the load loading means are placed on the base plate, and the indenter holding plate is mounted on the base plate. Since it was supported by a stand that was separated from the base and made independent of the load measuring means, the weight of the heating / cooling means and the load loading means, and the power supply cable connected to these means, By avoiding the elastic force of the circulating water hose and the thermocouple from being applied to the load measuring means, the load measuring means can measure only the press-fit load that presses the indenter with high accuracy.

(4) By using the device of the present invention, with the temperature of the sample specimen and the indenter precisely controlled, the indenter is brought into contact with the sample surface at an arbitrary speed, and the load P and the contact area A synchronized with the time axis. Can be measured continuously.
(5) Since either one of the measured load P or the contact area A is used as a control parameter, the closed loop control for freely controlling the contact state is possible. It is possible to give various dynamic stimuli to the sample specimen by freely controlling the speed thereof.
(6) By using the apparatus of the present invention, the mechanical characteristics of a sample specimen having both non-time-dependent characteristics, time-dependent characteristics, or both characteristics can be obtained. Can be quantitatively evaluated.
(7) The mechanical characteristics desired to be evaluated are quantitatively determined by optimally selecting evaluation formulas such as elastic characteristics, elasto-plastic characteristics, plastic characteristics, viscoelastic characteristics, viscosity characteristics, and flow characteristics. In addition, it is possible to evaluate various mechanical properties as a function of temperature by proceeding with the analysis based on these evaluation results, and to determine thermochemical characteristic values such as activation energy. .

It is sectional drawing which shows the Example of this invention. It is sectional drawing (front view) which shows the 2nd Example of this invention. It is sectional drawing (side view) which shows the 2nd Example of this invention. It is sectional drawing (front view) which shows the 3rd Example of this invention. It is sectional drawing (side view) which shows the 3rd Example of this invention. It is sectional drawing which shows the Example of the heating / cooling means of this invention. It is sectional drawing which shows the 2nd Example of the heating / cooling means of this invention. It is sectional drawing which shows the 3rd Example of the heating / cooling means of this invention. It is a figure of the sample holder of the Example of this invention. It is a figure of the holding plate and jig which fix the indenter of the Example of this invention.

  Next, embodiments of the present invention will be described in detail. The following examples show preferred examples of the present invention, and the present invention is not limited to the examples. Absent.

The present invention will be described by taking as an example an apparatus configuration using a Peltier element as a heating / cooling thermo-module. The reason why the Peltier element is employed in the thermostatic device is that the Peltier element has the excellent characteristics listed below. The Peltier device has advantages suitable for viscoelastic characteristics and plasticity evaluation by microindentation, which requires precision measurement technology.
1) A solid device having no moving parts.
2) Have two functions of heating and cooling by switching the current direction.
3) The temperature can be precisely controlled.
4) Wide temperature range from -100 ° C to + 100 ° C.
5) A cooling medium such as liquid nitrogen is not required.
6) Because there is no flow of cooling medium, it must be quiet and free from vibration.
7) It must be small and light.
8) Local heating and cooling are possible.

  However, a case where a mechanical test in a region exceeding the temperature range of 4) described above is naturally considered. In this case, for example, liquid nitrogen can be selected on the low temperature side, a ceramic heater or the like can be selected on the high temperature side, and heating / cooling means of a system that circulates the liquid medium can also be used. These are heating / cooling means that require piping such as hoses and tubes for circulating the liquid medium, or wiring for supplying power to the heater. There is no problem to use as a heating / cooling means.

  FIG. 1 is a sectional view schematically showing an apparatus according to an embodiment of the present invention. The sample 1 is placed on the sample holder 2 having a recess and is in direct contact with the heating / cooling means 19. Since these are placed on the base plate 33 of the internal frame 32, they are independent of the load cell type electronic balance 30. On the other hand, the transparent indenter 13 made of diamond, sapphire or the like is fixed to a transparent and highly rigid indenter holding plate with an illumination optical path and a contact surface observation optical path, and is directly connected to the load cell type electronic balance 30 via the heat insulating support 11. ing.

  The position adjustment of the indenter 13 and the sample 1 can be performed by the coarse movement XYZ stages 26, 27, and 28. Fine movement for finally bringing the sample 1 to be inspected into contact with the indenter 13 is performed by piezo. This is done by the actuator 25. The power source for driving and the signal cable by the electric stage and the piezoelectric actuator are also placed on the inner frame 32 and are independent of the load cell type electronic balance 30.

  The thermostat is surrounded by a container (chamber 3) that can be filled with dry air, nitrogen gas, or the like, and when the sample 1 of the test sample is cooled, dew condensation and ice adhesion (freezing) are prevented. Furthermore, the observation window 4 opened in the chamber 3 is heated to an appropriate temperature above the dew point by the heater 18 to prevent condensation on the surface on the optical microscope side, so that optical measurement is possible. Therefore, the contact area A between the sample 1 of the test sample and the indenter 13 can be measured by the optical microscope 17 having the objective lens 15 through the observation window 4.

  FIG. 2 is a front sectional view showing the outline of the apparatus of the second embodiment of the present invention. FIG. 3 is a side sectional view showing an outline of the apparatus of the second embodiment of the present invention. In this example, there is no internal frame 32, and the indenter 13 is directly connected to the electronic balance 30 via the indenter holding plate 14 and the heat insulating support jig 11, so that the heating / cooling means and the feeding cables 20 and 21 for the actuator are provided. In addition, the signal cables 22 to 24 of the electric stage, the feeding cable and the circulating cooling water tube 10, and the thermocouple 34 are independent.

  FIG. 4 is a front sectional view showing the outline of the apparatus of the third embodiment of the present invention. FIG. 5 is a side sectional view showing an outline of the apparatus of the third embodiment of the present invention. In this example, there is no internal frame 32, and the sample specimen 1 and the heating / cooling means 19 are supported by a driving force transmission jig 37, which is an arm connected to the Z-axis fine movement actuator 25. It is independent of the balance 30.

  Furthermore, the load cell type electronic balance 30 and driving means by the actuator 25 and the electric stages 26 to 28 are placed outside the chamber 3 through the bellows 36, and the volume of the chamber 3 is small. The heat-insulating support jig 11 is arranged so as to surround the heating / cooling means 19 and the four outer peripheral surfaces of the sample specimen holder, so that heat does not enter and exit from the heating / cooling means and the outside world. Thus, increasing the heat insulation expands the soaking area in the vicinity of the sample specimen, the time to reach soaking becomes faster, temperature control becomes easier, and leads to a reduction in the total time taken for the test, There is an effect.

  FIG. 6 is a sectional view schematically showing an embodiment of the heating / cooling means of the present invention. In fixing the Peltier element 105 and the sample holder, in order to obtain a large temperature difference ΔT, the heating / cooling surface to be brought into thermal contact with the sample holder 2 and the spacer block 107 and the heat sink 104 through which waste hot water flows are brought into contact. Insulation is necessary between the waste heat surface to be generated. In general, an adiabatic connection bolt 103 such as an engineering polymer can be used. Further, since the heat absorption amount of the Peltier element 105 is relatively small, it is necessary to provide an enclosure with a heat insulating material 108 such as a closed pore sponge.

  FIG. 7 is a cross-sectional view schematically showing a second embodiment of the heating / cooling means of the present invention. FIG. 8 is a cross-sectional view schematically showing a third embodiment of the heating / cooling means of the present invention. In order to increase the amount of heat absorption, the heating / cooling means in FIG. 7 uses two one-stage Peltier elements 105, and the heating / cooling means in FIG. 8 uses two three-stage Peltier elements, Is sandwiched from the left and right. In this case, the Peltier element 105 and the sample holder are fixed to each other by heat-insulating connection bolts 103 such as engineering polymer in order to insulate the heating / cooling surface and the waste heat surface and to increase the temperature difference ΔT. .

  FIG. 9 shows an embodiment of a square sample holder 2 having a recess. By providing a notch window connected to the recess, it is possible to observe the positional relationship between the tip of the indenter and the surface of the sample sample from the side, and the sample holder has a coarse motion that brings the index surface close to the tip of the indenter. Contributes to improving operability. In addition, if a long-acting micrometer 38 is attached to the chamber 3, it is possible to confirm whether the indenter and the surface of the sample specimen are close to each other through the notch of the specimen holder. This is possible with the enlarged display.

  The sample holder 2 is provided with a recess shallower than the sum of the height of the indenter 13 and the sample thickness. By placing the sample sample in this recess, the sample holder 2 and the indenter holding plate 14 are spatially close to each other. Thus, the constant temperature holding temperature of the sample 1, the sample holder 2, the indenter 13, and the indenter holding plate 14 of the test sample can be made uniform.

  FIG. 10 shows an example of a holding means for the indenter 13. By reducing the contact area of the contact point, the heat shielding effect that stops the inflow and outflow of heat is improved, so that three-point support via a high-rigidity heat insulating material 109 such as an engineering polymer is desirable.

  As described above in detail, the present invention has been developed in view of the above-described problems of the prior art, and relates to a mechanical property measurement / testing apparatus. Enables continuous observation of the indentation state of the indenter into the specimen of the specimen, and enables quantitative measurement of the load load measured with high precision and the contact area measured by optical image analysis from the optical image at the same time. The present invention is useful for realizing a new mechanical property measuring and testing apparatus capable of evaluating various mechanical property values of a test sample with high accuracy from the relationship.

DESCRIPTION OF SYMBOLS 1 Sample sample 2 Sample holder 3 Chamber 4 Observation window 5 Hermetic connector 6 Dry gas inlet 7 Dry gas outlet 8 Circulating cooling water inlet 9 Circulating cooling water outlet 10 Circulating cooling water tube 11 Insulation type support 12 Illumination 13 Transparent indenter (diamond, sapphire, etc.)
14 Indenter holding plate 15 Optical microscope objective lens 16 Focusing actuator 17 Optical microscope 18 Observation window fogging prevention heater 19 Heating / cooling means 20 Heating / cooling means power supply cable 21 Piezoactuator power supply cable 22 X-axis stage control Signal cable 23 Y-axis stage control signal cable 24 Z-axis stage control signal cable 25 Z-axis piezo actuator 26 X-axis stage 27 Y-axis stage 28 Z-axis stage 29 Z-axis coarse movement stage 30 Electronic balance 31 Electronic balance signal cable 32 Inside Frame 33 Base 34 Thermocouple 35 Z-axis coarse stage control signal cable 36 Bellows 37 Driving force transmission jig 38 Long-acting microscope 101 Waste heat circulating water inlet 102 Waste heat circulating water outlet 103 Heat insulation type connecting bolt 104 Heat sink 10 Peltier element 106 Peltier element feeding cable 107 spacer block 108 heat insulating material (such as closed pores sponge-)
109 Highly rigid insulation materials (engineering polymers, etc.)

Claims (9)

A transparent indenter that is press-fitted into the test sample, an optical means for observing the surface of the indenter in contact with the sample through the indenter, a load-loading means that press-fit the indenter into the sample, and a load-measuring means that measures the load to be pressed A mechanical property measurement test apparatus comprising: an image photographing means for photographing an image of a contact surface of an indenter on a sample surface; and an image recording / analyzing means,
An indenter is attached to the lower surface of a horizontal and transparent indenter holding plate, and the optical means is arranged above the indenter holding plate so that the contact surface of the indenter with the sample can be observed through the indenter holding plate. In addition, a thermostatic device for holding the sample in a heated / cooled state is arranged, and the contact area with the sample into which the indenter is press-fitted is optically continuously measured. A mechanical property measurement tester characterized by enabling measurement of physical properties.   A sample holder holding a sample, heating / cooling means of a constant temperature device, and the load loading means are placed on a base plate of an internal frame, and an indenter holding plate to which an indenter is attached is attached to the base plate. The load measuring means is supported by a stand that is separately installed, and the weight of the heating / cooling means and the load loading means, and the elasticity of the power supply cable, circulating water hose, and thermocouple connected to these means are The mechanical characteristic measuring and testing apparatus according to claim 1, wherein measurement of the press-fitting load of the indenter is performed while avoiding being applied to the indenter.   The mechanical property measurement test apparatus according to claim 2, wherein the load measurement resolution is 0.01 mgf or more.   4. The mechanical property measuring and testing apparatus according to claim 2, wherein a heating / cooling means is brought into contact with the sample holder to heat / cool the sample.   The mechanical property measurement test apparatus according to any one of claims 2 to 4, wherein the heating / cooling means is a Peltier element.   The mechanical property measuring and testing apparatus according to any one of claims 2 to 5, wherein the lower part of the optical means is covered with a chamber filled with a dry gas to prevent the occurrence of condensation and icing.   The mechanical property testing apparatus according to claim 6, wherein an observation window is provided on a ceiling surface of the chamber between the optical means and the indenter holding plate so that the contact surface of the indenter with the sample can be observed by the optical means. .   The sample holder is provided with a recess shallower than the sum of the height of the indenter and the sample thickness, and the sample is placed in this recess so that the sample holder and the indenter holding plate are spatially close to each other. The mechanical property measurement test apparatus according to any one of claims 2 to 7, wherein the constant temperature holding temperature of the holder, the indenter, and the indenter holding plate is made uniform.   The mechanical property measurement test apparatus according to any one of claims 2 to 8, wherein an indenter held by an indenter holding plate is supported via a heat insulating material to block heat from entering and exiting.

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