JP2857807B2 - Manufacturing method of long tubular preform by spray-deposit method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a long tubular preform by spray deposit.

[0002]

2. Description of the Related Art In general, the spray deposit method involves atomizing molten metal with an inert gas,
A method in which finely pulverized droplets are rapidly cooled and solidified during scattering and deposited on a collector to obtain a preform (formed material) having a desired shape (for example, JP-B-54-29985 and JP-B-56-12220). And JP-A-64-152
No. 64, etc.) and has features such as the ability to form a uniform microstructure by rapid solidification, no macro segregation, and good workability / forgeability as compared with the ordinary casting method. I have. In addition, the spray deposit method has a lower porosity and a higher density preform than the thermal spraying method in which a group of molten metal particles are sprayed onto the surface of a coating material to form a laminated coating, and furthermore, the productivity is improved. It has high features. However, when such rapid solidification is performed extremely, porosity is generated, and a high-density preform cannot be obtained. In other words, the cause of this porosity is that if the cooling by gas becomes too extreme, the ratio of solid phase particles in the particles deposited on the preform will increase, and the liquid phase and semi-molten It is considered that the gap between solid phase particles becomes porosity as it is because the number of particles decreases, and when the particle temperature becomes relatively low, the particles are less likely to flatten at the time of collision, and shadow Is formed. If the temperature of the particles that come later is in a molten state that is sufficiently high, the shadow portion can be filled, but if the temperature is low, it is thought that porosity will not be filled. Thus, the cause of porosity generation in the preform is thought to be related to temperature, but is still unclear. For example, when manufacturing a tubular preform, a porosity layer may be generated in the vicinity of the tube collector. When this is analyzed, it is considered that the temperature of the particles in contact with the collector becomes low, and porosity is generated for the above-described reason. Therefore, it is conceivable to preheat the tube collector. When applying high-frequency preheating, plasma preheating, etc. as this preheating method, it is said that discontinuity of preheating and a temperature difference in the longitudinal direction occur in the case of a tubular long object, and there is still partial porosity generation. There was a problem. On the other hand, in the above-mentioned Japanese Patent Application Laid-Open No. 64-15264, in a method of manufacturing a composite metal material using a spray deposit method, before spray depositing for different kinds of metals,
A method of manufacturing a composite metal material in which a separately placed preheating molten metal is caused to flow down onto a plate-shaped base material to form a coating layer on the base material, and a spray flow is deposited on the coating layer for a different type of metal is shown. However, in such a manufacturing method, a coating layer of a molten metal for preheating is interposed in order to increase the bonding strength between the dissimilar metal and the base material, and furthermore, in such a manufacturing method, the thickness of the coating layer is kept constant. Therefore, there is a problem that it is not useful for manufacturing a long tubular preform.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems at once, and its gist is to provide an atomizer for ejecting an inert gas to a ceiling side of a chamber. Providing a first container containing molten metal for performing spray deposit, receiving a spray flow from the atomizer, and
A tube collector that can be rotated and moved in the longitudinal direction is horizontally laid through the chamber, and the spray deposit is provided on the upstream side in the moving direction of the tube collector and on the ceiling side of the chamber. A second container containing a preheating molten metal having the same quality as the molten metal to be provided is provided, and a preheating metal flow is caused to flow down from the second container, and a metal film is formed on the entire circumference of the rotating collector. After forming and preheating this, the spray flow is deposited, thereby melting the porosity layer on the collector side of the preform and suppressing the porosity. Manufacturing method.

[0004]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described in detail with reference to an embodiment shown in the accompanying drawings. FIG. 1 is a schematic view of an apparatus according to an embodiment of the present invention. This embodiment is suitable for manufacturing a long tubular preform of a ferrous or non-ferrous metal by a spray deposit apparatus (a so-called Osprey apparatus). Things. In the figure, reference numeral 1 denotes a long tube collector, which penetrates the chamber 2 in the lateral direction and
Are supported by collector supports 3 and 3 provided on the outside of the robot, and rotate at 5 to 500 rpm.
Slow down from right to left. On the ceiling side of the chamber 2, a container 4 such as a preheating tundish or a crucible is provided via a nozzle (not shown) on the upstream side in the moving direction of the collector 1, and a tundish or spray deposit on the downstream side. A container 5 such as a crucible is provided via an atomizer 6. These containers 4 and 5 contain the same molten metal 7, but the molten metal in the preheating container 4 is maintained at a slightly high temperature. Further, a thin metal film 8 is formed on the collector 1 by flowing a metal flow 9 from the preheating container 4. The temperature of the metal film 8 is measured by a thermometer such as a pyrometer (not shown). The flow rate of the stream 9 is controlled. The spray flow 10 from the spray-deposit container 5 forms a tubular preform 11 in the same manner as in a normal spray-deposit apparatus. Immediately below the preheating container 4, a saucer 1 made of a refractory material is provided.
2 is provided to receive the metal stream 9 that could not be captured by the collector 1. The spray stream 10 that cannot be captured by the collector 1 is collected by a dust collector (not shown) via, for example, an exhaust gas ventilator 13 in the same manner as a normal spray deposit apparatus. In the present embodiment, first, the metal flow 9 is caused to flow down on the collector 1 rotating at a low speed, and the metal film 8
And preheat the collector 1 uniformly in the axial direction. The preheated portion of the collector 1 is moved immediately below the spray deposit container 5 to deposit the spray stream 10. Therefore, in the general preform 11, the collector 1 side is at a low temperature and a porosity layer is generated. However, according to the present embodiment, the collector 1 is preheated by the previously coated metal film 8 and the generation of porosity is prevented. Further, the porosity layer can be dissolved by the metal film 8 to eliminate the porosity.

[0005]

According to the present invention, it is possible to prevent porosity from being generated over the entire length of the long tubular preform on the collector side. In particular, since the tube collector extends laterally through the chamber, a long tubular preform can be formed, and the porosity layer is preheated by forming a metal film of the same quality as the spray deposit material. As the porosity was suppressed by melting, the preheating metal flow was allowed to flow down on the rotating collector to form a metal film all around the collector. As a result, a high-quality preform can be provided. Of course,
Peeling between the preform and the collector is good.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tubular collector 2 Chamber 4 Container for preheating 5 Container for spray deposit 8 Metal film 11 Tubular preform

Claims (1)

(57) [Claims] 1. A first container containing a molten metal for performing spray deposition is provided on an upper side of a chamber via an atomizer that ejects an inert gas, and receives a spray flow from the atomizer, and rotation and longitudinal movement collectors for each possible and the tube of,
Molten metal for carrying out the spray deposit is placed laterally through the chamber, on the upstream side in the moving direction of the tube collector, and on the ceiling side of the chamber.
A second container containing a preheated molten metal of the same quality as that described above , and flowing a preheat metal flow from the second container to form a metal film all around the rotating collector. And preheating it, then depositing the spray stream,
The porosity layer on the collector side of the preform is melted to
A method for producing a long tubular preform by spray deposit, characterized by suppressing porosity .