JP2007141346A - Magnetic head slider material, magnetic head slider, and manufacturing method of magnetic head slider material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic head slider material that is strong and capable of reducing the level differences on the air bearing surface, and to provide a magnetic head slider using it and a manufacturing method of the magnetic head slider material. <P>SOLUTION: The magnetic head slider material is made from a sintered material containing alumina, titanium carbide, and carbon at a rate that the titanium carbide is 20-120 pts.wt. and the carbon is 0.8-1.6 pts.wt. when the weight of alumina is set to 100 pts.wt. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic head slider material, a magnetic head slider, and a method for manufacturing a magnetic head slider material.

  A magnetic head slider including a thin film magnetic head was first used in a hard disk drive in 1979, and the magnetic head slider at this time is generally called a mini slider (100% slider). After that, the magnetic head slider progresses down to a micro slider (70% slider) about 70% of the size of the mini slider, and then down to a nano slider (50% slider) about 50% of the size of the mini slider. It has been.

  This magnetic head slider generally has a laminate including a thin film magnetic head on a substrate. In such a magnetic head slider, a laminated structure including a thin film magnetic head is laminated on a substrate to form a laminated structure, and then the laminated structure is cut in parallel to the lamination direction to form an exposed surface of the thin film magnetic head. The exposed surface is then lapped (polished) to obtain an air bearing surface.

When manufacturing a conventional magnetic head slider, for example, as described in Patent Document 1 below, a high-strength sintered body mainly composed of alumina and titanium carbide, so-called Altic sintering. The body is used as a substrate for a magnetic head slider.
JP-A-57-82172

  At present, a magnetic head slider called a pico slider (30% slider), which is about 30% of the size of a mini-slider, has become mainstream. In the future, it is expected to shift to a femto slider (20% slider) about 20% of the size of the mini slider.

  Along with the miniaturization of such a magnetic head slider, in the lapping process when forming the air bearing surface, the step of the air bearing surface caused by the difference in polishing amount between the substrate and the laminated body laminated on the substrate is reduced. It is demanded.

  The present invention has been made in view of the above-described problems, and can provide a magnetic head slider material that can reduce a step on the air bearing surface and has sufficient strength, a magnetic head slider using the same, and a magnetic head. It aims at providing the manufacturing method of the material for sliders.

  As a result of intensive studies by the present inventors, the polishing speed of the AlTiC sintered body used as the substrate of the conventional magnetic head slider is extremely low compared with the polishing speed of the laminated body including the thin film magnetic head. It has been found that sometimes the amount of polishing of the laminate becomes too large compared to the amount of polishing of the substrate, resulting in a large step. Furthermore, the present inventors have found that the polishing rate of a sintered body having a predetermined composition containing alumina, titanium carbide, and carbon is sufficiently higher than the polishing rate of a conventional Altic sintered body. I came up with the invention.

  The magnetic head slider material of the present invention contains alumina, titanium carbide and carbon, and 20 to 120 parts by weight of titanium carbide and 0.8 to 1.6 parts by weight of carbon when the weight of alumina is 100 parts by weight. It is a sintered body.

  The magnetic head slider of the present invention includes a substrate made of a sintered body and a laminate including a thin film magnetic head formed on the substrate. The sintered body contains alumina, titanium carbide and carbon, and 20 to 120 parts by weight of titanium carbide and 0.8 to 1.6 parts by weight of carbon when the weight of alumina is 100 parts by weight.

  According to these inventions, this sintered body has a higher polishing rate than the AlTiC sintered body used for the conventional magnetic head slider material. Therefore, the substrate using the magnetic head slider material has a higher polishing rate. The difference between the polishing rate and the polishing rate of the laminated body including the thin film magnetic head is sufficiently smaller than the conventional one. Thus, when manufacturing the magnetic head slider, in detail, a multilayer structure including a thin film magnetic head is laminated on a substrate made of the magnetic head slider material to form a multilayer structure, and in the stacking direction of the multilayer structure. When a magnetic head slider is manufactured by lapping parallel cross sections, a step is less likely to occur between the laminate and the substrate on the air bearing surface formed by lapping. Further, this magnetic head slider material has a sufficiently smooth surface and a sufficient strength.

  In the magnetic head slider material and magnetic head slider of the present invention, when the carbon concentration in the sintered body is less than 0.8 part by weight, the polishing rate is higher than that of a substrate made from a conventional Altic sintered body. It is insufficient. On the other hand, if the carbon concentration in the sintered body exceeds 1.6 parts by weight, the polishing rate is insufficient as compared with a substrate made from a conventional artic sintered body, and the surface of the polished surface is smooth. The nature is also insufficient.

  The reason why such a tendency is obtained is not clear, but can be considered as follows, for example. When carbon is added to a sintered body containing alumina and titanium carbide, it is considered that the grain growth of alumina and titanium carbide during the sintering is suppressed, thereby increasing the polishing rate of the sintered body. If the carbon concentration is too low, the above-described effects are too low, and if the carbon concentration is too high, the sinterability gradually decreases, so the surface smoothness tends to deteriorate.

  Further, in the magnetic head slider material and the magnetic head slider of the present invention, when the titanium carbide concentration in the sintered body is less than 20 parts by weight, the rigidity of the material is lowered and the strength is lowered. On the other hand, when the density | concentration of the titanium carbide in a sintered compact exceeds 120 weight part, sinterability will fall and intensity | strength will fall. The concentration of titanium carbide in the sintered body is preferably 40 to 80 parts by weight.

  In the magnetic head slider material and the magnetic head slider, the sintered body preferably further contains 0.5 to 10 parts by weight of titania when the weight of alumina is 100 parts by weight. In this case, the sinterability of the sintered body is improved and the strength is easily improved. The titania concentration in the sintered body is preferably 4 to 8 parts by weight.

  The method for manufacturing a magnetic head slider material according to the present invention includes a step of preparing a powder compact and a step of sintering the compact in a non-oxidizing atmosphere. The powder compact includes alumina, titanium carbide and carbon, and 20 to 120 parts by weight of titanium carbide and 0.8 to 1.6 parts by weight of carbon when the weight of alumina is 100 parts by weight.

  According to this, the above-mentioned magnetic head slider material can be suitably manufactured.

  Here, in the step of preparing a molded body, a powder containing alumina, a powder containing titanium carbide, and a powder containing carbon are mixed to obtain a mixed powder, and this mixed powder can be molded.

  Further, in the step of preparing a molded body, a mixture containing alumina and powder containing titanium carbide and an organic substance is obtained, and the mixture is heat treated in a non-oxidizing atmosphere to carbonize the organic substance in the mixture. Thus, a mixed powder can be obtained, and the mixed powder can be molded.

  Furthermore, in the step of preparing a molded body, a powder containing alumina, a powder containing titanium carbide and an organic substance are mixed to obtain a mixture, the mixture is molded, and the molded mixture is heat-treated in a non-oxidizing atmosphere. Thus, the organic matter in the mixture can be carbonized.

  According to the present invention, it is possible to realize a magnetic head slider having a sufficient strength and a reduced step on the air bearing surface. Thereby, a magnetic head slider having a smaller size can be manufactured, and further higher density can be achieved.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

(Material for magnetic head slider)
First, the magnetic head slider material according to this embodiment will be described. The magnetic head slider material according to the present embodiment is a sintered body containing alumina (Al ₂ O ₃ ), titanium carbide (TiC), and carbon (C). Here, in the sintered body, alumina and titanium carbide each form crystal grains. In the sintered body, carbon is a free component that is not chemically bonded to alumina or titanium carbide, and is mainly present at the crystal grain boundaries of alumina or titanium carbide.

  Here, the carbon concentration in the magnetic head slider material is 0.8 to 1.6 parts by weight when the weight of alumina is 100 parts by weight.

  Here, if the carbon concentration is higher than 1.6 parts by weight, the polishing rate tends to be insufficient as compared with the conventional artic sintered body, which is not preferable. On the other hand, if the carbon concentration is lower than 0.8 part by weight, the polishing rate is not sufficient as compared with the conventional Altic sintered body and the surface smoothness of the polished surface is deteriorated, which is not preferable.

  Incidentally, the AlTiC sintered body used as a conventional magnetic head slider material is made by mixing and sintering alumina powder and titanium carbide powder. The titanium carbide powder usually inevitably contains about 0.05 to 0.15% of carbon. Accordingly, assuming that the weight of alumina in the Altic sintered body is 100 parts by weight, the conventional Altic sintered body usually contains about 0.01 to 0.18 parts by weight of carbon. The carbon concentration of this conventional Altic sintered body is sufficiently lower than the carbon concentration of the magnetic head slider material of this embodiment.

  The concentration of titanium carbide in the magnetic head slider material of this embodiment is 20 to 120 parts by weight when the weight of alumina is 100 parts by weight. In such a range, a sufficiently strong magnetic head substrate can be obtained. If the concentration of titanium carbide is less than 20 parts by weight, the rigidity tends to decrease and the strength tends to decrease. On the other hand, when the concentration of titanium carbide exceeds 120 parts by weight, the sinterability tends to decrease and the strength tends to decrease.

  Further, it is preferable that the magnetic head slider material further contains titania. A suitable concentration of titania is 0.5 to 10 parts by weight when the weight of alumina is 100 parts by weight. When the magnetic head slide material contains titania, the sinterability becomes high and the strength can be easily increased.

  The magnetic head slider material may contain other components to the extent that the characteristics are not affected.

(Method for manufacturing magnetic head slider material)
Next, a first method for manufacturing such a magnetic head slider material will be described.

  First, alumina powder, titanium carbide powder, and carbon powder, and titania powder as an additive as required are prepared.

  Here, the average particle diameter of the raw material alumina powder is preferably 0.1 to 1 μm, and more preferably 0.4 to 0.6 μm.

  Moreover, it is preferable that the average particle diameter of a titanium carbide powder is 0.1-3 micrometers, and it is more preferable that it is 0.5-1.5 micrometers. The titanium carbide powder may contain carbon.

  Moreover, it is preferable that the average particle diameter of carbon powder is 20-100 nm. As the carbon powder, for example, a powder made of carbon such as carbon black and ethylene black can be used.

  Moreover, it is preferable that the average particle diameter of a titania powder is 0.1-3 micrometers, and it is more preferable that it is 0.5-1 micrometer.

  And these powders are mixed in organic solvents, such as ethanol, IPA, and 95% denatured ethanol, for example, and mixed powder is obtained. If water is used as a solvent, the solvent and titanium carbide cause a chemical reaction and the titanium carbide powder is oxidized, so that water cannot be used.

  Here, in the mixed powder, when the total weight of alumina is 100 parts by weight, the alumina powder, titanium carbide powder, carbon powder, titania so that the weights of the titanium carbide powder, carbon, and titania satisfy the above-mentioned conditions, respectively. Blend powder.

  Here, it is preferable to mix the powder in a ball mill or an attritor. Moreover, it is preferable to mix powder for about 10 to 100 hours. In addition, as a mixing medium in a ball mill or an attritor, for example, it is preferable to use an alumina ball having a diameter of about 1 to 20 mm.

  Next, the mixed powder is spray granulated. Here, for example, it may be spray-dried in a hot air of about 60 to 200 ° C. of an inert gas such as nitrogen or argon containing almost no oxygen, whereby a granulated product of the mixed powder having the above composition is formed. can get. Here, for example, the particle size of the granulated product is preferably about 50 μm to 200 μm.

Next, if necessary, the above-mentioned organic solvent is added to adjust the liquid content of the granulated product so that the organic solvent is contained in the granulated product by about 0.1 to 10% by weight. Examples of the organic solvent used for adjusting the liquid content include organic solvents such as ethanol, IPA, and 95% denatured ethanol. Usually, the organic solvent used when mixing the powder is used. In this case, too, when water is used as a solvent, the solvent and titanium carbide cause a chemical reaction and the titanium carbide powder is oxidized, so that water cannot be used.

Next, the granulated product is filled into a predetermined mold, and primary molding is performed by cold pressing to obtain a molded body. Here, for example, a granulated product is filled in a metal or carbon mold for forming a disk having an inner diameter of 150 mm, and cold-pressed at a pressure of about 5 to 15 MPa (about 50 to 150 kgf / cm ² ). do it.

Subsequently, the obtained molded body is hot pressed to obtain a sintered body. Here, for example, the firing temperature is 1200 to 1700 ° C., the pressure is 10 to 50 MPa (about 100 to 500 kgf / cm ² ), and the atmosphere is a non-oxidizing atmosphere such as vacuum, nitrogen, or argon. Note that the non-oxidizing atmosphere is used to suppress oxidation of titanium carbide. Moreover, it is preferable to use a carbon mold for forming the mixed powder. The sintering time of the molded body is preferably about 1 to 3 hours.

  Thereby, the magnetic head slider material is completed. Here, the shape of the material for the magnetic head slider is not particularly limited, and for example, a disk-shaped substrate having a diameter of 6 inches and a thickness of 2.5 mm or a rectangular substrate can be used.

  Next, a second manufacturing method of such a magnetic head slider material will be described.

  In the first manufacturing method described above, carbon powder is used, but in the second manufacturing method, an organic substance is used instead. Specifically, first, alumina powder, titanium carbide powder, and an organic substance are mixed to obtain a mixture. Here, an organic substance is not specifically limited, For example, polyvinyl alcohol, an acrylic resin, a butyral resin etc. can be illustrated. Moreover, you may add additives, such as a titania powder, to a mixture as needed.

  Subsequently, the mixture is heat-treated in a non-oxidizing atmosphere such as a vacuum atmosphere or a nitrogen atmosphere to carbonize the organic matter in the mixture. Here, the carbonization conditions can be arbitrarily set according to the type of organic matter, etc., for example, by performing heat treatment at 600 ° C. for about 5 hours in a vacuum drying furnace or the like, including alumina, titanium carbide, and carbon, A mixed powder containing titania or the like can be obtained as necessary.

  Thereafter, the mixed powder may be formed and sintered in the same manner as in the first manufacturing method.

  When the organic material is used in this way, the carbon can be uniformly dispersed, and the time required for the carbon dispersion can be shortened.

  In order to obtain a dense material for a magnetic head slider, it is preferable to perform molding after carbonizing the organic material as described above, but it is also possible to carbonize the organic material after molding.

  Specifically, after obtaining a mixture containing alumina powder, titanium carbide powder, organic matter, and the like, the mixture is molded in the same manner as in the first production method before carbonization. And the molded object of the mixture containing this organic substance can be heat-treated as described above to carbonize the organic substance to obtain a molded article containing alumina, titanium carbide, carbon and the like.

Here, in the second production method, the concentration of each powder in mixing alumina powder, titanium carbide powder and organic matter, and further titania powder etc. as necessary is carbonized after carbonizing these mixtures What is necessary is just to predetermine so that the quantity of an alumina, titanium carbide, carbon, and titania in the mixed powder or molded object may become the density | concentration prescribed | regulated to a 1st manufacturing method. Thereby, a molded body having the same composition as that of the first manufacturing method is obtained.

(Magnetic head slider)
Next, a magnetic head slider using the magnetic head slider material will be described with reference to FIG.

  The magnetic head slider 11 of the present embodiment has a thin film magnetic head 10 and is mounted on a hard disk device (not shown) provided with a hard disk. In this hard disk device, magnetic information is recorded and reproduced by a thin film magnetic head 10 on a recording surface of a hard disk rotating at high speed.

The magnetic head slider 11 according to the embodiment of the present invention has a substantially rectangular parallelepiped shape. In FIG. 1, the front surface of the magnetic head slider 11 is a recording medium facing surface that is disposed facing the recording surface of the hard disk, and is an air bearing surface (ABS).
Called S. Further, 11a grooves are formed on the air bearing surface in a direction orthogonal to the track width direction.

  When the hard disk rotates, the magnetic head slider 11 is floated by the air flow accompanying this rotation, and the air bearing surface S is separated from the recording surface of the hard disk. The air bearing surface S may be coated with DLC (Diamond Like Carbon) or the like.

  The magnetic head slider 11 includes a substrate 13 made of the magnetic head slide material described above, and a laminated body 14 formed on the substrate 13 and including the thin film magnetic head 10. More specifically, in the present embodiment, the substrate 13 has a rectangular parallelepiped shape, and the laminate 14 is formed on the side surface of the substrate 13.

  The upper surface 14a of the laminated body 14 forms the end face of the magnetic head slider 11. The upper surface 14a of the laminated body 14 has recording pads 18a and 18b and reproducing pads 19a and 19b connected to the thin film magnetic head 10. Is attached. The thin film magnetic head 10 is provided in the laminated body 14, and a part of the thin film magnetic head 10 is exposed to the outside from the air bearing surface S. In FIG. 1, the thin film magnetic head 10 embedded in the stacked body 14 is indicated by a solid line in consideration of easy recognition.

  Such a magnetic head slider 11 is mounted on a gimbal 12 and connected to a suspension arm (not shown) to constitute a head gimbal assembly.

  FIG. 2 is a schematic cross-sectional view (II-II schematic cross-sectional view in FIG. 1) in a direction perpendicular to the air bearing surface S and perpendicular to the track width direction in the magnetic head slider 11. As described above, the magnetic head slider 11 includes the substantially rectangular plate-shaped substrate 13 and the stacked body 14 stacked on the side surface of the substrate 13. The laminated body 14 includes a thin film magnetic head 10 and a coat layer 50 surrounding the thin film magnetic head 10.

  The thin film magnetic head 10 includes a GMR (Giant Magneto Resistive) element 40 as a reading element for reading magnetic information of a hard disk and a writing element for writing magnetic information to the hard disk in order from the side closer to the substrate 13. The inductive electromagnetic transducer 60 is a so-called composite thin film magnetic head.

  The electromagnetic conversion element 60 employs a so-called in-plane recording method, and includes a lower magnetic pole 61 and an upper magnetic pole 64 in order from the substrate 13 side, and further includes a thin film coil 70.

  The end portions of the lower magnetic pole 61 and the upper magnetic pole 64 on the air bearing surface S side are exposed to the air bearing surface S, and the exposed portions of the lower magnetic pole 61 and the upper magnetic pole 64 are separated by a predetermined distance so that the recording gap G is formed. Forming. On the other hand, the end 64B of the upper magnetic pole 64 on the side away from the air bearing surface S is bent toward the lower magnetic pole 61, and this end 64B is on the side of the lower magnetic pole 61 on the side away from the air bearing surface S. Magnetically connected to the end. Thus, a magnetic circuit that sandwiches the gap G is formed by the upper magnetic pole 64 and the lower magnetic pole 61.

  The thin film coil 70 is disposed so as to surround the end portion 64B of the upper magnetic pole 64, and generates a magnetic field between the recording gaps G by electromagnetic induction, thereby recording magnetic information on the recording surface of the hard disk.

  Although not shown, the GMR element 40 has a multilayer structure and is exposed to the air bearing surface S. The GMR element 40 detects a change in the magnetic field from the hard disk using the magnetoresistive effect and reads magnetic information.

  The GMR element 40 and the electromagnetic conversion element 60 and the upper magnetic pole 64 and the lower magnetic pole 61 are separated from each other by an insulating coat layer 50. The thin film magnetic head 10 itself is also covered with the coat layer 50 except for the air bearing surface S. The coat layer 50 is mainly formed of an insulating material such as alumina. Specifically, an alumina layer formed by sputtering or the like is usually used. Such an alumina layer usually has an amorphous structure.

  The thin film magnetic head 10 may be a vertical recording system instead of the in-plane recording system. Further, instead of the GMR element 40, an AMR (Anisotropy Magneto Resistive) element using an anisotropic magnetoresistance effect, a TMR (Tunnel-type Magneto Resistive) element using a magnetoresistance effect generated at a tunnel junction, or the like is used. Also good.

  Further, the coat layer 50 may further include a magnetic layer or the like that magnetically insulates between the GMR element 40 and the electromagnetic conversion element 60.

  Next, a method for manufacturing the magnetic head slider 11 as described above will be described.

  First, as described above, as shown in FIG. 3, a substrate 13 on which the above-described magnetic head slider material is formed in a disk wafer shape is prepared. Next, as shown in FIG. 4A, a laminated body 14 including the thin film magnetic head 10 and the coat layer 50 is laminated on the substrate 13 by a known method. Here, the multilayer body 14 is formed in the multilayer body 14 such that a large number of thin film magnetic heads 10 are arranged in a matrix.

  Subsequently, the substrate 13 on which the laminate 14 is laminated is cut into a predetermined shape and size. Here, for example, by cutting as shown by the dotted line in FIG. 4A, a plurality of thin film magnetic heads 10 are arranged in a line as shown in FIG. Are formed so as to be exposed to the side surface 100BS.

  Then, a so-called lapping process is performed in which the air bearing surface S is formed by polishing the side surface 100BS of the bar 100B. In this lapping process, the substrate 13 and the laminated body 14 laminated thereon are polished simultaneously and in a direction intersecting with the laminating direction (direction of arrow X in FIG. 2).

Here, in the present embodiment, the substrate 13 is made of the aforementioned magnetic head slider material, that is,
It is made of a sintered body containing alumina, titanium carbide, and carbon and blended at a predetermined concentration. Therefore, the polishing rate of the substrate 13 is sufficiently higher than the polishing rate of the substrate made of the conventional Altic sintered body, and the polishing rate of the substrate 13 is the polishing of the laminated body 14 including the thin film magnetic head 10. It is about the same as the speed.

  Therefore, when lapping is performed, the difference in polishing amount between the stacked body 14 and the substrate 13 becomes extremely small, and the step D (see FIG. 5) between the stacked body 14 and the substrate 13 is larger than the conventional one. Is significantly smaller than Thereby, for example, the air bearing surface S can be in a substantially flat state. Specifically, for example, the step D can be set to 1.2 nm or less.

  Further, the maximum height Rmax (JIS B 0601-1982) of the polished surface is sufficiently small, and the surface smoothness can be extremely increased.

  Therefore, a femto slider or a slider having a size smaller than that can be suitably formed, and further high-density recording is facilitated. Furthermore, since the substrate 13 of this embodiment has sufficient strength, the reliability is sufficient.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in more detail, this invention is not limited to these Examples at all.

  In this example, a plurality of substrates of magnetic head slider materials having different constituent materials were manufactured, and the bending strength, polishing rate, and surface roughness were measured for each.

(Examples 1-5)
First, alumina powder (average particle size 0.5 μm), titanium carbide powder (average particle size 0.5 μm, containing 0.1 wt% carbon), titania powder (average particle size 0.1 μm), carbon powder (carbon black) , Average particle size 35 nm) each weighed a predetermined amount, pulverized and mixed with IPA (isopropyl alcohol; boiling point 82.4 ° C.) for 30 minutes in a ball mill, and then granulated by spray granulation at 150 ° C. in nitrogen. Got.

  Here, the alumina powder, the titanium carbide powder, the carbon powder, and the titania powder were mixed at a concentration that satisfies the following conditions in the granulated product.

  In Examples 1 to 5, the concentrations of titanium carbide and titania with respect to alumina were the same, and when the weight of alumina was 100 parts by weight, titanium carbide was 60 parts by weight and titania was 6.7 parts by weight. The weight of carbon is 0.89 parts by weight in Example 1, 1.12 parts by weight in Example 2, 1.28 parts by weight in Example 3, and 100 parts by weight of alumina. In Example 4, it was 1.44 parts by weight, and in Example 5, it was 1.6 parts by weight. Carbon is the total value of carbon powder-derived and titanium carbide powder-derived.

Subsequently, each of the obtained granulated materials is subjected to primary molding at about 0.5 MPa (50 kgf / cm ² ), and then hot pressing is performed in a vacuum atmosphere for 1 hour at a sintering temperature of 1600 ° C. and a press pressure of about 30 MPa (about The material for the magnetic head slider was obtained for each example by firing at 300 kgf / cm ² ). Thereafter, these pieces were cut into sections of about 20 × 20 × 1.8 mm, and the sections were polished using a slurry containing diamond particles having a diameter of 0.1 μm using a single-side polishing machine. Here, the polishing conditions were a tin plate rotation speed of 37.5 times / min, a load of 2550 g, an Oscar motor rotation speed of 55 times / min, and a polishing time of 10 minutes. And the thickness before and behind grinding | polishing was measured and the grinding | polishing speed | rate for each Example was acquired by remove | dividing the change of thickness by grinding | polishing time. Moreover, the bending strength of each board | substrate was measured on the conditions of JISR1601 (1995) using the Shimadzu Corporation testing machine. Furthermore, the surface roughness Rmax (JIS B 0601-1982) of the surface of the sintered body after polishing was measured with a surface roughness measuring device.

(Comparative Example 1-7)
Comparative Example 1 was the same as Example 1 except that no carbon powder was added and the weight of carbon was changed to a weight derived from titanium carbide powder, that is, 0.06 parts by weight. In Comparative Example 2-5, the amount of carbon powder added was 0.23 parts by weight, 0.48 parts by weight, 1.7 parts by weight, 3.4 parts by weight, 8.4 parts by weight, and 17 parts by weight, respectively. The same as Example 1 except that.

  These conditions and results are shown in a table in FIG. The polishing rate was expressed as a ratio of the polishing rate of Comparative Example 1 to 100 and each polishing rate as a ratio to the polishing rate of Comparative Example 1. Here, the polishing rate of Comparative Example 1 was 1.7 μm / 10 min.

  Implementation in which the weight of carbon is 0.8 to 1.6 parts by weight compared to the polishing rate of the section of Comparative Example 1 made from a conventional Altic sintered body having a weight of carbon of less than 0.2 parts by weight. In the sections according to Examples 1 to 5, a sufficiently high polishing rate (160 or more) was obtained, and the surface smoothness was sufficient (20 nm or less). On the other hand, in Comparative Examples 1-7 where the weight of carbon does not satisfy the above-described conditions, the polishing rate and the surface smoothness were not sufficient.

  In addition, the cross-sectional SEM photograph of the section | slice of Example 1 and the cross-sectional SEM photograph of the section | slice of the comparative example 1 are shown in order to Fig.7 (a) and FIG.7 (b). It is understood that when the amount of carbon increases, grain growth of alumina or titanium carbide is suppressed. In addition, when the average particle diameter of the alumina was measured from the SEM photograph, it was 0.3 μm in Example 1 and 0.5 μm in Comparative Example 1.

FIG. 1 is a perspective view of a magnetic head slider according to an embodiment of the present invention. FIG. 2 is a view taken along the line II-II in the magnetic head slider of FIG. FIG. 3 is a perspective view for explaining the method of manufacturing the magnetic head slider according to the embodiment of the present invention. FIG. 4A and FIG. 4B are perspective views subsequent to FIG. 3 for explaining the method of manufacturing the magnetic head slider according to the embodiment of the present invention. FIG. 5 is a conceptual cross-sectional view showing a state where the bar of FIG. 4B is polished. FIG. 6 is a table showing the compositions and characteristics of the magnetic head substrates of Examples 1 to 5 and Comparative Examples 1 to 7. 7A is a cross-sectional SEM photograph of the magnetic head substrate according to Example 1, and FIG. 7B is a cross-sectional SEM photograph of the magnetic head substrate according to Comparative Example 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Thin film magnetic head, 11 ... Magnetic head slider, 13 ... Substrate, 14 ... Laminated body, 50 ... Coat layer, D ... Step, S ... Air bearing surface.

Claims (8)

  Magnetic head slider material comprising alumina, titanium carbide and carbon and a sintered body containing 20 to 120 parts by weight of titanium carbide and 0.8 to 1.6 parts by weight of carbon when the weight of alumina is 100 parts by weight .   The magnetic head slider material according to claim 1, wherein the sintered body further includes 0.5 to 10 parts by weight of titania when the weight of alumina is 100 parts by weight. A substrate made of a sintered body, and a laminate including a thin film magnetic head formed on the substrate,
The sintered body is a magnetic head slider containing alumina, titanium carbide and carbon, and 20 to 120 parts by weight of titanium carbide and 0.8 to 1.6 parts by weight of carbon when the weight of alumina is 100 parts by weight.   4. The magnetic head slider according to claim 3, wherein the sintered body further contains 0.5 to 10 parts by weight of titania when the weight of alumina is 100 parts by weight. A step of preparing a powder compact containing 20 to 120 parts by weight of titanium carbide and 0.8 to 1.6 parts by weight of carbon when alumina, titanium carbide and carbon are included and the weight of alumina is 100 parts by weight;
Sintering the molded body in a non-oxidizing atmosphere;
A method of manufacturing a magnetic head slider material comprising:   6. The magnetic head slider material according to claim 5, wherein in the step of preparing the formed body, a powder containing alumina, a powder containing titanium carbide, and a powder containing carbon are mixed to obtain a mixed powder, and the mixed powder is formed. Manufacturing method.   In the step of preparing the molded body, a powder containing alumina, a powder containing titanium carbide and an organic substance are mixed to obtain a mixture, and the organic substance in the mixture is carbonized by heat-treating the mixture in a non-oxidizing atmosphere. The method for producing a magnetic head slider material according to claim 5, wherein a mixed powder is obtained and the mixed powder is molded.   In the step of preparing the molded body, a mixture is obtained by mixing powder containing alumina, powder containing titanium carbide, and organic matter, molding the mixture, and heat-treating the molded mixture in a non-oxidizing atmosphere. 6. The method of manufacturing a magnetic head slider material according to claim 5, wherein the organic substance in the mixture is carbonized.

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