WO2007037431A1

WO2007037431A1 - Sintered body and method for producing same; sliding member, film-forming material and die for hot extrusion molding each using such sintered body; and hot extrusion molding apparatus and hot extrusion molding method each using such die for hot extrusion molding

Info

Publication number: WO2007037431A1
Application number: PCT/JP2006/319577
Authority: WO
Inventors: Hiroshi Hamashima
Original assignee: Kyocera Corporation
Priority date: 2005-09-29
Filing date: 2006-09-29
Publication date: 2007-04-05
Also published as: CN101273150B; JP4709223B2; EP1930457A1; JPWO2007037431A1; CN101273150A; EP1930457A4

Abstract

By using a sintered body composed of 58-92.5% by mass of TiCN, 0.01-1% by mass of Ti, 0.01-2% by mass of TiC, 0.01-2% by mass of TiN and the balance of TaC, Ni and Cr, there can be obtained a sliding member, film-forming material and die for hot extrusion molding which exhibit high strength, high hardness, high toughness and high sliding properties in an environment of about 400-600˚C, and a hot extrusion molding apparatus using such a die for hot extrusion molding.

Description

Sintered body, manufacturing method thereof, sliding member using the sintered body, film forming material, hot extrusion die and hot extrusion molding device using the hot extrusion die and hot Extrusion method

Technical field

[0001] The present invention relates to a sintered body, a manufacturing method thereof, a sliding member using the sintered body, a film-forming material, a hot extrusion die, and a heat using the hot extrusion die. The present invention relates to a hot extrusion molding apparatus and a hot extrusion molding method.

Background art

Conventionally, when an extruded material is formed by hot extrusion of an aluminum alloy or the like, as shown in FIGS. 5 and 9, hot extrusion that becomes a bearing portion incorporated in a die case 102 of a hot extrusion molding apparatus 111 An extrusion material 6 having a desired shape has been formed by extruding an aluminum alloy billet 5 heated to about 400 to 500 ° C. from a through-hole 101a serving as a guiding portion of the forming die 101.

[0003] The material of the hot extrusion die 101 is usually cemented carbide (hereinafter referred to as cemented carbide) or SKD61. The cemented carbide has high hardness and is comparable to a metal material. SKD61 is widely used because the hardness at high temperature is difficult to deteriorate.

[0004] However, when carbide or SKD61 is used as the material for the above-described hot extrusion die for aluminum alloy such as aluminum alloy at a high temperature described above, the carbide is used at a high temperature of about 400 to 500 ° C. Due to thermal degradation, hardness and strength are significantly reduced. In addition, SKD61 does not provide high hardness enough to withstand use, and, for example, aluminum adheres to the inner peripheral surface 101b of the through hole 101a that becomes the guiding portion when the extruded material 6 of aluminum alloy is formed. . As a result, carbide and SKD61 cannot withstand long-time molding, and the hot extrusion die 101 is damaged or worn. Had occurred.

[0005] Recently, in order to solve such problems, heat produced with conventional carbide or SKD61 is used. The ceramic cermet is coated or thickened on the inner peripheral surface 101b of the through-hole 101a, which is the guiding portion of the hot-extrusion die 101, and the hot-extrusion die 101 is made of ceramic. That is being sought. However, since many problems cannot be solved, it is popularized to the general public.

[0006] For example, Patent Document 1 discloses a technique in which a ceramic is coated on the inner peripheral surface 101b of the through hole 101a of the hot extrusion forming die 101 that becomes a bearing portion used for hot extrusion molding of an aluminum alloy. It is disclosed in Document 2 and Patent Document 3.

[0007] In Patent Documents 1 and 2, the base material of the hot extrusion die 101 is a high-speed steel, and TiC is coated at a thickness of 1 μm on at least a portion that becomes a sliding surface with the extruded material. It is disclosed that the sliding resistance of the inner peripheral surface 101b of the through hole 101a serving as the guiding portion of the extruded material 6 and the hot extrusion molding die 101 can be reduced, and the extrusion speed can be improved by 20% compared to the conventional technique.

[0008] Further, in Patent Document 3, a ceramic layer such as TiC, VC, TaC, WC, etc. is formed on the inner peripheral surface 101b of the through-hole 101a, which serves as a guide portion of the hot extrusion die 101, by a discharge hardening process. : It is proposed to cover in the range of LO m, and the base material of the hot extrusion die 101 is not mentioned, but it is disclosed that the wear resistance is improved by the coated ceramic layer Has been.

[0009] Further, in Patent Document 4, it is proposed that the cermet is thickened in the range of 4 to 15 mm in thickness on the inner peripheral surface 101b of the through hole 101a serving as the guiding portion of the hot extrusion molding die 101 of SKD material. Has been. There, the composition of cermet is Cr C, NbC, WC, TiC, SiC

3 2

One type or two or more types of carbide-based ceramics are selected, and they also have a Ni-based or NiCr-based alloy matrix strength, and the ceramics are contained in an amount of 10 to 30 wt%. As a result, the surface force of the inner peripheral surface 101b of the through-hole 101a during hot extrusion molding can secure hardness and prevent wear even if it is assumed that the surface force reaches 700 ° C at a depth of 4mm. It is disclosed that cracking due to thermal shock during extrusion molding can be suppressed and peeling of the reinforced portion can be prevented.

[0010] Further, in Patent Document 5, the main body of the hot extrusion die 101 is referred to as ZrO—YO, ZrO.

2 2 3 Use zirconium oxide ceramics such as MgO or ceramics such as Si N silicon nitride.

2 3 4

It has been proposed. There, the surface to the extruded material 6 during hot extrusion of aluminum It has been disclosed to increase the extrusion speed while suppressing the occurrence of defects.

[0011] On the other hand, in Patent Document 6, a titanium carbonitride (TiCN) sintered body is proposed as a material suitable for an injection-molded material and die-cast sleeve that require high-temperature pressure strength in the fabrication of molten aluminum. A titanium carbonitride cermet sintered body using 64 parts by weight of titanium carbonitride (TiCN) powder, 30 parts by weight of titanium carbide (TiC) powder, and 6 parts by weight of AMF alloy iron powder as an auxiliary agent. Making is disclosed.

Patent Document 1: JP 2000-63972 A

Patent Document 2: Japanese Patent Laid-Open No. 2000-63973

Patent Document 3: Japanese Patent Laid-Open No. 2000-102816

Patent Document 4: Japanese Unexamined Patent Publication No. 2000-63975

Patent Document 5: Japanese Patent No. 2535025

Patent Document 6: Japanese Unexamined Patent Publication No. 2003-321718

Disclosure of the invention

Problems to be solved by the invention

[0012] However, when TiC is coated on the inner peripheral surface 101b of the through-hole 101a proposed in Patent Documents 1 and 2 with 1 μm, which is proposed in Patent Documents 1 and 2, TiC coated with the base material, high-speed steel Because of the large difference in thermal expansion coefficient, the coating is easily peeled off. In addition, TiC is prone to an acid-oxidation phenomenon in an environment of 450 ° C. or higher, and there is a problem of thermal deterioration in which a substitution reaction occurs in TiO, which causes a significant deterioration in the TiC force of high-hardness materials.

2

[0013] In addition, when the ceramic layer proposed in Patent Document 3 is coated on the inner peripheral surface 101b of the through-hole 101a in a thickness range of 2 to 10 μm by electric discharge machining, it is coated with the base material. In addition, since the difference in thermal expansion coefficient between the ceramic layers was large, it was difficult to avoid the occurrence of coating peeling.

[0014] Further, in the case where the carbide cermet is thickened in the thickness range of 4 to 15 mm on the inner peripheral surface 101b of the through hole 101a of the SKD material proposed in Patent Document 4, the composition of the carbide cermet is Cr. C, NbC, WC, TiC

3 2, One or more types of SiC carbide ceramics Force selected Power of high sliding characteristics with an aluminum alloy, for example, can be obtained even if only 10 to 30 wt% of any of these carbide ceramics is used. I can't. Therefore The aluminum alloy extruded material 6 has a problem that the aluminum tends to adhere to the inner peripheral surface 101b of the through-hole 101a, which becomes the guiding portion during molding, and breaks or is pressed due to wear. It was not possible to avoid problems such as scratches on the output material 6 and defective dimensions.

[0015] Further, in the case where the hot extrusion die 101 main body proposed in Patent Document 5 is made of a zircoure ceramic or silicon nitride ceramic, sufficient strength to withstand hot extrusion of an aluminum alloy is obtained. The reason why it cannot be obtained was that the inner peripheral surface 101b of the through-hole 101a was damaged or had a bad dimension on the extruded material 6 formed by wear or was not able to avoid the problem!

[0016] Further, Patent Document 6 discloses a method of manufacturing a TiCN-TiC cermet sintered body as a material suitable for molten aluminum forging material. However, TiC is an acidic solution in an environment of 450 ° C or higher. The TiC force of high-hardness materials is prone to occur and the hardness is significantly deteriorated.

2 Due to the thermal deterioration that causes the conversion reaction, it was not suitable as a die material for hot extrusion molding such as aluminum alloy.

[0017] In view of the above problems, the present invention is a sintered body having high strength, high hardness, high toughness, and high slidability, and a slide using the same, particularly in an environment of about 400 to 600 ° C. It is an object of the present invention to provide a moving member, a film forming material, a hot extrusion die, and a hot extrusion molding apparatus using the hot extrusion die.

Means for solving the problem

[0018] The sintered body of the present invention has a TiCN force of 8 to 92.5 mass% and Ti of 0.01 to 1 mass. / ₀ , TiC is 0.01-2 mass%, TiN is 0.01-2 mass%, and the balance is TaC, Ni, Cr. And 1 to Ta C: L 1 Mass ^_0/0, Ni 3 to 13 mass ^_0/0, may have 3 to 13 mass% of Cr.

[0019] The sintered body preferably has two peaks in its particle size distribution. One peak has a particle size range of 1.0 to 1.3 m, and the other peak has a particle size of 1.4 to 1. In the above particle size distribution, crystal grains in the particle size range of 1.0 to 1.3 / zm and crystal particles in the particle size range of 1.4 to 1.7 μΐη are 3: 2 to 1 : The weight ratio should be 1. Furthermore, the crystal grains of the sintered body are preferably spherical.

[0020] The sliding member and the film forming material of the present invention are formed using the sintered body, and examples thereof include a slider and a target material. [0021] The hot extrusion die of the present invention is formed using the sintered body. The hot extrusion molding die preferably has a through hole in the vicinity of the center of the plate shape, and at least an amorphous film is formed on the inner peripheral surface of the through hole. Further, it is preferable that the amorphous film is made of alumina or silicon carbide, and the amorphous film has a thickness of 0.2 to 1.2 m.

[0022] In the hot extrusion molding apparatus of the present invention, the hot extrusion molding die is attached to one end side of a cylindrical die case, and the other end side of the die case is connected to one end side of the cylindrical container. And an extrusion mechanism for extruding the extruded material into the container is placed in the container.

[0023] The method for producing a hot extrusion die of the present invention comprises an average particle size of 0.3 to 0.7 ^ πι (ΤίΟΝ powder, an average particle size of 1.2 to 2 111 7: 3 to 9: 1, add TaC powder with an average particle size of 1.5 μm or less, Ni powder and Cr powder with an average particle size of 2 μm or less, and grind with solvent It has the process of mixing and making it a slurry.

The invention's effect

[0024] The sintered body of the present invention has a TiCN force of 8 to 92.5 mass% and Ti of 0.01 to 1 mass. / ₀ , TiC is 0.01 to 2% by mass, and TiN is 0.01 to 2% by mass. Therefore, the hot extrusion die of the present invention formed using the sintered body is particularly about 400 Even in a high temperature environment of ˜600 ° C., it is possible to maintain high strength and high toughness and to suppress the sliding resistance of the extruded material to a low level.

[0025] Further, the hot extrusion die 1 has a through hole in the vicinity of the center of the plate shape, and at least an amorphous film is formed on the inner peripheral surface of the through hole. When preheating at around 400 to 600 ° C, the amorphous film prevents oxidation of the inner peripheral surface of the through-holes, so the strength of the hot extrusion die before hot extrusion is reduced (the bond strength between particles is reduced). ) Can be prevented.

[0026] Further, since the amorphous film is made of alumina or silicon carbide, it has an acid resistance action up to about 600 ° C, so that a hot extrusion die for preheating before hot extrusion molding is used. The effect of preventing oxidization of the inner peripheral surface of the through hole can be further improved.

[0027] The preferred thickness of the amorphous film is 0.2-1.2 μm, and the thickness is small. If both are 0.2 m or more, the surface of the hot extrusion die can be protected without unevenness, and the problem of acidification from the surface layer at high temperatures can be prevented. And since it is originally intended to prevent oxidation during preheating, 1. is sufficient. 1. If the film thickness is significantly greater than 2 m, the adhesion of the film will decrease due to internal stress, especially for thick films exceeding 2 m. There is a risk of peeling. When the preheating temperature is about 500 ° C or less, an amorphous film of silicon carbide is formed, and when the preheating temperature is about 650 ° C or less, an alumina amorphous film is formed to prevent oxidation of the inner peripheral surface of the through hole. it can.

[0028] Then, the hot extrusion molding die is attached to one end side of a cylindrical die case, the other end side of the die case is attached to one end side of the cylindrical container, and the extruded material is If an extrusion mechanism for container force extrusion is arranged in the container and used as a hot extrusion molding device, the hot extrusion die has excellent strength, hardness and toughness at high temperatures. It is possible to prevent wear and breakage of the extrusion die, and to suppress scratches and dimensional problems on the extruded material, and to greatly improve the continuous molding time of hot extrusion molding.

[0029] Further, in the method for producing a hot extrusion die according to the present invention, a raw material powder to be a TiCN cermet material is obtained by using a TiCN powder having an average particle size of 0.3 to 0.7 m and an average particle size of 1 2—2 μm (mixed with Ti CN powder in a ratio of 7: 3 to 9: 1, and further with a TaC powder with an average particle size of 1. Since the raw powder is pulverized and mixed with a solvent to form a slurry, the coarse TiCN crystal particles are filled with the fine TiCN crystal particles so that they are covalently bonded. Sintering or solid-phase bonding is promoted, so that the TiCN crystal particles can be sintered with low decomposition of Ti, TiC and TiN. When the die for hot extrusion molding of the present invention is used, the inclusion of Ti, TiC and TiN is kept low. It has the effect of suppressing acid resistance, and as a result, high slidability can be secured.

Brief Description of Drawings

[0030] FIG. 1 shows an example of a hot extrusion molding apparatus incorporating the hot extrusion die of the present invention. It is sectional drawing shown.

FIG. 2 is a perspective view of a test piece of the present invention.

FIG. 3 is a cross-sectional view showing a method for measuring a three-point bending strength.

FIG. 4 (a) is a plan view of a hot extrusion die of the present invention, and (b) is a cross-sectional view thereof.

FIG. 5 is a cross-sectional view of a conventional hot extrusion die.

FIG. 6 is a TG-DTA differential thermal analysis chart of a TiCN cermet material used as a hot extrusion die of the present invention.

FIG. 7 is a TG-DTA differential thermal analysis chart of an alumina amorphous film.

FIG. 8 is a TG-DTA differential thermal analysis chart of a silicon carbide amorphous film.

FIG. 9 is a cross-sectional view of a conventional hot extrusion molding apparatus.

FIG. 10 is a diagram showing the composition of Ti, TiC, and TiN of the hot extrusion die of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The sintered body of the present invention is composed of TiCN 58-92.5% by mass, TiO. 01-1% by mass, TiCO. 01-2% by mass, TiNO. 01-2% by mass, the balance being TaC, Ni, Cr. is important. Further, it is desirable to have TaCl˜: L 1% by mass. Further, it is desirable to have 3 to 13% by mass of Ni and 3 to 13% by mass of Cr. The balance becomes inevitable impurities such as Fe.

[0032] It is preferable that the sintered body has two peaks in the particle size distribution, and the peaker is within a particle size range of 1.0 to 1.3 111 and 1.4 to 1.7 / zm, respectively. There is power. On the other hand, if the peak is less than 1.0 m, agglomeration of only fine particles occurs immediately and the aggregation of fine particles immediately becomes the core of abnormal particle growth, so there is a problem that the toughness and strength deteriorate. If it is larger than 1.3 m, there is a problem that TiCN crystal particles decompose into Ti, TiC and TiN due to insufficient covalent sintering or solid phase bonding. On the other hand, if the other peak is less than 1.4 m, there is a problem that the particle size becomes too large to ensure slidability, and if it exceeds 1.7 m, covalent bonding sintering or solid phase bonding is insufficient. Therefore, there is a problem that TiCN crystal particles decompose into Ti, TiC, TiN.

[0033] The ratio of the peak in the range of 1.0 to 1.3 m and the peak in the range of 1.4 to 1.7 m is 3: 2 to A weight ratio of 1: 1 is preferred. 1. When the peak at 0 to 1.3 m is 60% or more, aggregation of fine particles tends to occur, and slidability cannot be ensured because it becomes the core of abnormal particle growth and degranulation and strength deterioration. There is a defect, and if it is less than 50%, there is a defect that TiCN crystal particles decompose into Ti, TiC and TiN due to insufficient covalent bonding sintering or solid phase bonding.

The two peaks in the particle size distribution of the sintered body are those in the desired particle size range by using TiCN raw material powder in which a fine powder having a predetermined particle size and a coarse powder are mixed at a predetermined mixing ratio. Can be obtained.

[0034] The crystal grains of the sintered body are preferably spherical. When the crystal grains are spherical, the slippage at the time of raw material extrusion on the die surface using the sintered body is stabilized.

[0035] The sintered body of the present invention can be used as a film forming material, such as a sliding member. When the sliding member formed using the sintered body is used for a hot extrusion die or a hot drawing die, high slidability can be obtained. Further, when the film forming material formed using the sintered body is formed on the sliding portion of a hot extrusion die or a hot drawing die, high slidability can be obtained.

FIG. 1 is a schematic longitudinal sectional view of a hot extrusion molding apparatus 11 in which a hot extrusion molding die 1 of the present invention is fitted in a cylindrical die case 2. For example, the extrusion 6 of aluminum alloy is formed by hot extrusion, which is a die, by placing a billet 5 in which a columnar lump such as an aluminum alloy is heated in a cylindrical container 3 and extruding it by an extrusion mechanism 4. A desired extruded material 6 is formed from the forming die 1.

The hot extrusion die 1 of the present invention is formed using the sintered body. The component content of the sintered body forming the hot extrusion die 1, TiCN58~92 5 wt%, TaCl~:. L 1 mass ^{_0/0, Ni3~13} mass ^{_0/0, Cr3~13} mass ^_0/0 was the, if TiCN is less than 58 wt%, it is impossible to obtain a high slip properties (high sliding property), and sinterability is remarkably TiCN exceeds 5 mass% 92. This is because the hardness decreases and high hardness and high strength cannot be obtained.

[0037] Further, when TaC is less than 1% by mass, the acid resistance and sinterability at high temperatures are deteriorated, and when it exceeds 11% by mass, the sliding characteristics are deteriorated. Also, if Ni and Cr are less than 3% by mass in each case, the sinterability cannot be lowered and densification cannot be ensured. In each case, if it exceeds 13% by mass, high hardness cannot be ensured and wear resistance is reduced.

[0038] Then, TiO. 01-1 mass ^_0/0, TiCO. 01-2 mass ^_0/0, TiNO. Was a 01-2 mass%, the Ti is 1 wt%, TiC is 2 mass%, This is because when TiN exceeds 2% by mass, TiC, TiN and Ti metal are present in more than desired amounts, and the acid resistance is reduced. As a result, the high slidability is significantly reduced. When this sintered body is used as a hot extrusion die 1, thermal degradation and slidability in a high temperature environment of about 400 to 600 ° C are achieved. A problem arises that is disturbed.

[0039] If Ti, TiC, and TiN are less than 0.01% by mass, local crystal growth proceeds, and the crystal grain state becomes non-uniform and the strength may deteriorate. It is important that the content of both TiN is 0.01% by mass or more.

[0040] According to TiCN, Ti, TiC and TiN described above, by sintering using a predetermined amount of TiCN raw material powder in which a predetermined fine powder and a coarse powder are mixed at a predetermined mixing ratio, Ti, TiC and TiN produced by the decomposition of TiCN can be obtained at the desired ratio.

[0041] Normally, once the molding of the extruded material 6 is interrupted, the inner peripheral surface lb of the through-hole la serving as the induction part of the hot extrusion molding die 1 is alkali-washed with NaOH or the like to obtain aluminum. When removing deposits such as alloys and reusing them, carbide or SKD61, which has been used as a conventional die material, may corrode the surface layer by these cleaning solutions, resulting in a significant reduction in surface hardness. However, the sintered body of TiCN-TaC-Ni-Cr as the main component of the hot extrusion die 1 of the present invention can be used any number of times until it can no longer be used due to wear that is not corroded by alkaline cleaning such as NaOH. Can be used repeatedly.

[0042] Further, the preferable surface roughness Ra of the inner peripheral surface lb of the through-hole la is 0.05 μm or less, and when Ra exceeds 0.05 m, the smoothness of the surface of the extruded material 6 is obtained. It becomes impossible.

[0043] The through-hole la is preferably formed near the center of the plate-shaped hot extrusion die 1 and an amorphous film lc is preferably formed at least on the inner peripheral surface lb of the through-hole la. . In hot extrusion of aluminum alloys, etc., preheating the inner surface of the hot extrusion molding device 11 at a temperature of about 400 to 600 ° C for the purpose of uniform heating of the billet 5 and air defoaming interposed inside. Perform for about 1 hour (hr). Therefore, the through-hole la during this preheating An amorphous film lc is formed for the purpose of preventing acidity of the inner peripheral surface lb.

[0044] That is, the TiCN cermet of the present invention is a material that is difficult to oxidize at a high temperature as compared with conventional carbide, SKD61, and carbide cermet, but a certain amount of oxidization cannot be suppressed. Therefore, it is desirable to form the amorphous film lc on the inner peripheral surface lb of the through hole la in order to prevent the bonding force between particles due to the acid salt from decreasing.

[0045] Further, the amorphous film lc is preferably formed of alumina or silicon carbide. Since the thermal oxidation reaction of alumina and silicon carbide starts at over about 600 ° C, if the preheating temperature at the time of hot extrusion is about 600 ° C or less, the acid on the inner peripheral surface lb at the time of preheating is used. It is possible to prevent a decrease in strength due to the 匕. More specifically, when the preheating temperature before forming the extruded material 6 is about 550 ° C or lower, a silicon carbide amorphous film lc is formed, and when it is about 600 ° C or lower, an alumina amorphous film lc is formed. Therefore, it is possible to prevent acidification of the inner peripheral surface lb of the through-hole la, and the material of the amorphous film lc can be appropriately selected depending on the preheating temperature.

[0046] The amorphous film lc is not necessarily limited to alumina or silicon carbide, but may be silicon nitride, titanium nitride, and titanium for hot extrusion molding for aluminum refrigerant tubes for heat exchangers. There is no problem even if it is used.

[0047] Further, it is desirable that the thickness t of the amorphous film lc is 0.2 to 1.2 μm. If the thickness t of the amorphous film lc is at least 0.2 m or more, there is no unevenness. The inner surface lb of the through-hole la can be protected, and the problem of oxidation from the surface layer at high temperatures can be prevented. On the other hand, if the thickness t of the amorphous film lc exceeds 1.2 μm, the adhesion of the film decreases particularly when the film thickness exceeds 2 μm. , Amorphous membrane lc may be peeled off during setting work. A more preferable thickness t of the amorphous film lc is 0.5 to 1. O / zm.

[0048] When the amorphous film lc is formed not only on the inner peripheral surface 1b of the through-hole la of the hot extrusion molding die 1, but also on the side surface Id, deterioration due to acid and soot from the surroundings can be suppressed.

[0049] In addition, when hot extrusion molding of the extruded material 6 is started, the amorphous film lc immediately peels and disappears due to the sliding resistance with the billet 5, but when the extruded material 6 absorbs oxygen and heat, the induction part 6 The contact temperature will drop and will not reach a level where acid will become a problem. [0050] However, as described above, when the molding of the extruded material 6 is interrupted and the molding is started again, the inner peripheral surface lb of the through-hole la is washed with an alkali such as NaOH to remove the adhered aluminum alloy. It may be removed and used again. In that case, in order to prevent oxidation at the time of preheating again, if the peeled amorphous film lc is reapplied, it can be used repeatedly without any problem.

Next, as shown in FIG. 1, the hot extrusion molding apparatus 11 of the present invention attaches the hot extrusion molding die 1 of the present invention to one end side of a cylindrical die case 2, and The other end side of the die case 2 is attached to one end side of the cylindrical container 3, and an extrusion mechanism 4 for extruding the extruded material 6 from the container 3 is arranged in the container 3. When the hot extrusion molding apparatus 11 is used for hot extrusion molding at a high temperature of about 400 to 600 ° C., the most damaging hot extrusion die 1 has excellent strength, hardness and toughness at high temperatures. Therefore, there is little risk of wear or breakage, so that the occurrence of scratches and dimensional problems on the extruded material 6 can be suppressed, and the continuous molding time can be greatly improved.

[0052] Next, a method for producing the hot extrusion die 1 of the present invention will be described.

[0053] The method for producing the hot extrusion die 1 according to the present invention comprises a fine powder having an average particle size of 0.3 to 0.7 111 and an average particle size of 1.2 to 2 as a raw material powder. 1 coarse powder of 111? ^ Powder is mixed in a predetermined amount at a ratio of 7: 3 to 9: 1, and 1 ^ powder with an average particle size of 1.5 or less and Ni with an average particle size of 2 m or less A predetermined amount of powder and Cr powder are added and pulverized and mixed with a solvent to form a slurry.

[0054] Here, the fine TiCN powder having an average particle size of 0.3 to 0.7 μm and the coarse TiCN powder having an average particle size of 1.2 to 2 μm are mixed with 7: 3 to 9 : The reason why the predetermined amount is mixed at a ratio of 1 is that the coarse TiCN crystal particles are filled with fine TiCN crystal particles in the sintering stage, thereby promoting covalent bonding sintering or solid phase bonding. This is because TiCN crystal particles can be sintered without being decomposed into Ti, Ti C, or TiN.

[0055] Then, the obtained slurry is dried and granulated by a known spray dryer.

[0056] Next, the powder produced by the above method is formed into a plate-like molded body by a known rubber press, and a desired shape is obtained by a known cutting process. If a through hole is formed in the vicinity of the center of the plate-shaped molded body in advance, the desired penetration can be achieved by wire electric discharge machining after the molded body is fired. Can be processed into through holes.

Next, the molded body is fired in a known vacuum furnace in an atmosphere reduced to 1.33 Pa or less at a maximum keep temperature of 1350 to 1500 ° C. for 1 hour (hr). When the calcination temperature is 1350 ° C or less, it is not sufficiently densified, and when it exceeds 1500 ° C, the metal component sublimes and the TiCN composition starts to decompose, so the preferred calcination temperature is 1350-1500 ° C.

[0058] Next, the obtained sintered body is formed into a desired shape by wire electric discharge machining and grinding, and then the inner peripheral surface lb of the through hole la of the extruded material 6 has a surface roughness Ra of 0.05 m. Polish with fluid barrels so that:

[0059] The force for producing the hot-extrusion die 1 of the present invention through the above steps When forming an amorphous film lc on the inner peripheral surface lb of the through-hole la, alumina or silicon carbide is formed by sputtering. It is desirable to form a film with a thickness t in the range of 0.2 to 1.2 m. The amorphous film lc may be formed not only on the inner peripheral surface lb of the through-hole la but also on the side surface Id. In this case, the amorphous film lc may be applied on both side surfaces Id.

[0060] As described above, the hot extrusion die 1 of the present invention and the hot extrusion molding device 11 of the present invention using the die 1 have high strength and wear resistance at high temperatures. It is suitable for hot extrusion molding of aluminum alloy extruded materials for home use and household use, but it can be suitably used particularly for molding refrigerant pipes such as in-vehicle radiators, intercoolers, and air conditioner condensers.

[0061] Further, the use is not limited to the above-described hot extrusion molding of an aluminum alloy, but is also suitable for hot extrusion molding of a copper alloy or a titanium alloy.

Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

[0063] [Example 1]

A sintered body made of TiCN cermet, which is the base material of the hot extrusion die 1 of the present invention, was prepared by dividing each powder into 6 levels. TiCN powder is a fine TiCN powder with an average particle size of 0.5 μm and a coarse TiCN powder with an average particle size of 1.7 μm mixed at a ratio of 8: 2, and the remaining amount of Put the average particle size of 1.2 111 clove powder and 1. 6 111 ^ powder and 1.4 m Cr powder into a SUS ball mill. A slurry was prepared by adding 3% of ethanol and paraffin wax in the same volume as the total powder, and paraffin wax in a total powder mass ratio of 48% (hr) for 48 hours (hr).

[0064] Here, when the total content of TiCN, TaC, Ni, and Cr is 100% by mass, the respective content is TiCN = 63% by mass, Ding & Ji = 11% by mass,? ^ = 13 wt%, 0 = 13 that the mass% Sample No. 1, TiCN = 79 mass ^_0/0, TaC = 6 mass ^_0/0, Ni = 7 mass ^_0/0, Cr = 8 Weight ^_0/0 and those that the sample No. 2, TiCN = 93 mass ^_0/0, TaC = l weight ^_0/0, Ni = 3 mass ^_0/0, Cr = 3 wt% as sample No. 3 of those did.

[0065] As a comparative example outside the scope of the present invention, the average particle size of the TiCN raw material powder and the ratio of the fine TiCN powder to the coarse TiCN powder were set to 8: 2 in the same manner as in the present invention example. component containing Yuryou is, TiCN = 60 wt%, TaC = 12 wt%, Ni = 14 wt%, Cr = 14 wt% and sample No. 4 things, TiCN = 63 mass ^_0/0, TaC = l weight ^_0/0, Ni = 18 mass ^_0/0, Cr = 18 wt ^_0/0, and sample No. 5 what was, TiCN = 96 mass ^_0/0, TaC = 0 mass ^_0/0, Ni = 2 mass. Sample No. 6 was obtained with ₀ / Cr and Cr = 2% by mass.

[0066] Further, a sample in which the mixing ratio of fine TiCN powder and coarse TiCN powder was changed was also added.

[0067] The TiCN powder is a fine TiCN powder with an average particle size of 0.5 μm and a coarse TiCN powder with an average particle size of 1.7 μm, and the rest is a TaC powder with an average particle size of 1. If, 1. using Cr powder of Ni powder and 1. 6 m, and TiCN = 79 mass ^_0/0, TaC = 6 mass ^_0/0, Ni = 7 wt%, and Cr = 8% by weight, the fine Samples Nos. 8 and 9 of the examples of the present invention were prepared by setting the mixing ratio of TiCN powder and coarse TiCN powder to 7: 3 and 9: 1, respectively. Samples Nos. 7 and 10 outside the scope of the present invention were prepared with the blending ratios of 6: 4 and 9.5: 0.5. Other additives and preparation methods are the same as described above.

[0068] Next, the obtained slurry was granulated by high-speed drying with a spray dryer at a temperature of 120 ° C and an exposure time of 1 second.

[0069] Thereafter, a rectangular parallelepiped molded body serving as a test piece for three-point bending strength after sintering was produced by a hydraulic hand press.

[0070] Then, the compact was fired at a maximum temperature of 1450 ° C for 1 hour (hr) in a vacuum oven using a vacuum furnace at a reduced pressure of 1.33 Pa to produce a sintered body of TiCN cermet did. [0071] Then, by grinding the sintered body using a surface grinder (using a # 400 standard resin diamond), as shown in Fig. 2, the test of the three-point bending test method based on JIS-R1601 The piece 12 was processed into a rectangular parallelepiped with a short side dimension 12a of 3mm, a long side dimension 12b of 4mm, and a length 12c of 40mm.

[0072] Samples Nos. 1 to 3, 8, and 9 of Examples of the present invention of the test piece 12 and Samples Nos. 4 to 7, and 10 of Comparative Examples outside the scope of the present invention were fired after firing. The composition analysis of the body and the three-point bending strength, Vickers hardness, and fracture toughness values after heat treatment at 550 ° C for 1 hour (hr) in an air atmosphere for each of 5 samples. Measured.

[0073] The composition analysis was performed using an X-ray diffractometer RINT1100 manufactured by Rigaku Corporation with X-rays of 40 kV and 40 mA. Here, the composition ratio of each component was determined by separately creating the diffraction peak force of each component when the sample was measured with an X-ray diffractometer. Calculated value The ratio of each component was calculated. In addition, since the measurement limit value is 0.01 mass%, “less than 0.01 mass%” is described as “−”.

[0074] Three-point bending strength ¾ Based on the three-point bending test method according to JIS-R1601, using a digital load tester manufactured by Aikoichi Engineering Co., Ltd., as shown in Fig. 3, span 1 3 force 30mm, cross The strength at which the test piece 12 breaks when the speed of the head 14 was 0.5 mm / min was measured.

[0075] Further, the Vickers hardness was measured according to JIS-R1610 using an AVK-A type hardness meter manufactured by Akashi Manufacturing Co., Ltd., HvLoad 10kg.

[0076] Also, according to the SEPB method (Single Edge Precracked B earn) according to fracture toughness value ίO IS-R1607, the hardness meter is AVK-A type manufactured by Akashi Seisakusho, and the universal testing machine is M ODEL1125 type manufactured by Instron, Autograph The AGS-500B type manufactured by Shimadzu Corporation and the optical length meter were measured using a Mitutoyo measuring machine.

[0077] According to the criteria for determining the three-point bending strength, Vickers hardness, and fracture toughness value, the three-point bending strength is 1150 MPa or more, the Vickers hardness is 1400 GPa or more, and the fracture toughness value is 10 MPa'm ^{1 The} overall evaluation was good (○) for those satisfying ^{/ 2} or more, and the ones satisfying one or more of them were considered unusable (X). The reason for this is that if the three-point bending strength is less than 1150 MPa, cracking due to insufficient strength is likely to occur during hot extrusion. Also, if the Vickers hardness is less than 1400 GPa, the wear resistance becomes insufficient, wear and deformation are likely to occur, and if the fracture toughness value is less than 10 MPa'm ^1/2 , it will be missing during hot extrusion. It is a force that easily causes cracks.

The results are shown in Table 1. The composition and characteristic values are average values of 5 samples.

[table 1]

. Note) "HCN mixing ratio (fine powder: coarse powder)

[0079] As shown in Table 1, the sintered compact samples No. 1, 2, and 3 used in the hot extrusion die 1 of the present invention have composition range forces TiCN58 to 92.5 mass ⁰ / _{0, TaCl~:} L 1 mass ^{_0/0, Ni3~13} mass%, in Cr3~13 mass%, appearance from 0.01 to 1 mass% of Ti by the TiCN is decomposed, TiC, appearance of TiN are both In the range of 0.01 to 2% by mass, the surface of the sintered body does not decrease the interparticle bonding force due to the acid even after the sintered body is heated to 550 ° C. 3 points bending Fracture strength is 1180MPa or more, Vickers hardness is 1460GPa or more, and fracture toughness value is 10M Pa 'm ^1/2 or more at high temperature because original high strength, high hardness and high toughness can be maintained. The overall evaluation is good as there is no surface degradation.

[0080] On the other hand, Sample No. 4, which is outside the scope of the present invention, was promoted by acidification on the surface of the sintered body after heat treatment at 550 ° C, resulting in a decrease in interparticle bonding force. Therefore, the three-point bending strength was 1040 MPa and the Vickers hardness was 1030 GPa. Sample No. 5 also showed that TaC was less than 1% by mass due to the appearance of Ti, TiC, and TiN due to the decomposition of TiCN, that Ti significantly exceeded 1% by mass, and that TiN was 2 Since it exceeded the mass%, the acidity of the surface of the sintered body was promoted after heat treatment at 550 ° C, and the bonding force between particles was reduced, and there was also low sinterability. Therefore, the three-point bending strength was 900MPa, the Vickers hardness was 1040GPa, and the fracture toughness was 7MPa'm ^1/2 . In Sample No. 6, the appearance of Ti, TiC, and TiN due to the decomposition of TiCN was less than 0.01% by mass, especially because TaC was less than 1% by mass. After heat treatment at 550 ° C, heat resistance deterioration and low sinterability are all, so the three-point bending strength is 890 MPa, Vickers hardness is 1180 GPa, and fracture toughness is 7 MPa'm ^V2. It was a low value, and the overall evaluation was bad for Sample Nos. 4, 5, and 6 and could not be used.

[0081] In addition, 0.4 to 0.47 mass% of Fe was detected in sample Nos. 2 to 4 and 6 as inevitable impurities. The inevitable impurities are preferably close to 0, but the temperature of deterioration caused by acid is high at 800 ° C. Therefore, when the temperature force when used as a die for hot extrusion molding is about 400 to 600 ° C, it does not cause deterioration of strength, etc. Therefore, the content of about 1% by mass is not a problem.

[0082] Furthermore, the mixing ratio of the fine TiCN powder and the coarse TiCN powder of the TiCN powder was set to 7: 3 and 9: 1. Samples Nos. 8 and 9 in the examples of the present invention promoted activation of sinterability and suppressed abnormal grain growth during sintering, so that the appearance of Ti, TiC and TiN could be suppressed. In addition, oxidation did not proceed under high temperature conditions, and the three-point bending strength, Vickers hardness, and fracture toughness values did not decrease, and the overall evaluation was good.

[0083] On the other hand, the mixing ratio of fine TiCN powder and coarse TiCN powder of TiCN powder is 6: 4, 9.5:

In Samples Nos. 7 and 10, which are outside the scope of the present invention as 0.5, in Sample No. 7, the crystal particles locally decomposed and enlarged, so that Ti, TiC, and TiN appeared at the time of sintering. As a result, as a result of the progress of acidification in a high temperature environment, Sample No. 7 has a three-point bending strength of less than 1150 MPa, Vickers hardness of less than 1400 GPa, and fracture toughness of 10 MPa'm ^1/2 Sample No. 10 had a Vickers hardness of less than 1400 GPa and a fracture toughness value of less than 10 M Pa'm ^1/2 .

From [0084] As a result, TiCN58～92 5 wt%, TaCl~:. L 1 wt%, Ni3～13 mass ^_0/0, with Cr3~13 mass%, appearance of Ti due to the TiCN is decomposed 0 01-1 mass. / ₀ , TiC, and TiN all appear in 0.01-2 mass% TiCN cermet material does not cause deterioration in strength, hardness, and toughness under high temperature environment. It can be seen that this is a suitable material for the die 1 base material.

[0085] [Example 2]

Dies for hot extrusion molding 1 and 101 shown in Fig. 4 (a) and (b) are manufactured and attached to a hot extrusion molding machine 11 and 111 to perform hot extrusion molding. Evaluation was conducted. Samples Nos. 11 to 13 of Example of the present invention and Sample No. 4 of Example 1 were produced by using the sintered bodies of Sample Nos. 1 to 3 of Example 1 to produce hot extrusion dies 1. Sample Nos. 14 and 15 using the sintered body of No. 6 are outside the scope of the present invention.

[0086] As a comparative example, the hot extrusion molding die 101 is made of 94% by mass of ZrO and 6% by mass of Y2O.

Sample No. 16 was made of zirco-yure ceramics with 2 2 3 force.

Further, as a comparative example, as shown in FIG. 5, the body of the hot extrusion die 101 is SKD 61, and the inner peripheral surface 101b of the through hole 101a is made of a cermet material made of NiCrZCr C ZNbC.

3 2

Reinforced part 7 with a thickness t of 5 mm made of Cr C—NbC with a composition of 25% by mass

3 2

This was designated as Sample No. 17. Note that the reinforced portion 7 of the cermet material is a discharge fusion method. Formed by the method.

[0087] It should be noted that in both the examples and comparative examples of the present invention, the thickness T of the hot extrusion dies 1, 101 is 20 mm, and the outer diameter Φ 1 is a disk-shaped force of 30 mm, and the vicinity of the center of the disk-shaped Through-holes la and 10 la are formed, and the through-holes la and 101a are rectangular slits having a width d of 1.5 mm and a length of 1 15 mm, and the four corners are formed from a C-plane c of about 0.5 mm. Yes.

[0088] The hot extrusion dies 1 and 101 are attached to the hot extrusion molding apparatuses 11 and 111, subjected to a preheating treatment at 500 ° C for 1 hour (hr), and then a temperature of 460 ° C. Then, hot extrusion of aluminum alloy was carried out. The molding conditions were such that the pressing force of the extrusion mechanism 4 was controlled so that the extrusion speed was 30 mZmin. Continuous molding was performed until abnormal flaws occurred on the surface of the extruded material 6.

Here, the criteria for judging the abnormality of the scratches generated on the surface of the extruded material 6 were a scratch depth of 10 m and a width of 20 / z m or more. This standard is not based on industry standards, but for example, aluminum refrigerant pipes for high-power air conditioners are more stringent because they are higher in pressure and use gas than before when they become free of CFCs! / It is predicted to become a scratch standard. The scratch was measured using a surface roughness meter manufactured by Kosaka Laboratory.

[0090] In the hot extrusion molding, the abnormality first appears as the surface state of the extruded material 6. At the same time, the hot extrusion dies 1, 101 are damaged, or the inner peripheral surface lb, 10 Peeling may occur in the lb, and confirmation including this breakage and peeling was performed. In all cases, the number of samples is one.

[0091] Then, the comprehensive evaluation when the continuous molding time until the occurrence of any of the above errors is less than 24 hours (hr) cannot be used (X), 24 hours (hr) or more, 36 hours (hr) Less than acceptable (△), 36 hours (hr) or more, and less than 48 hours (hr) as good (◯). The reason is that the continuous extrusion time of less than 24 hours (hr), which is the conventional level, is used because the hot-extrusion molding die 101 made of current carbide or SKD61 has a life of less than half a day to less than one day. It is not possible and is the expected value. 1. 5 to 2 days are good and the middle is acceptable. The results are shown in Table 2.

[Table 2]

*: An indication outside the scope of the present invention

1) Abnormalities are scratches on the extruded material

2) Abnormality is damage to the hot extrusion die

[0092] As can be seen from the results in Table 2, the sample Nos. 11 to 13 of the examples of the present invention can perform the continuous forming time of the aluminum alloy extruded material 6 for at least 42 hours (hr) or more. The reasons for the occurrence were all scratches on the extruded material 6. At that time, cracks in the hot extrusion die 1 and cracking of the inner peripheral surface lb were not observed, and the overall evaluation was good. Met.

[0093] Samples Nos. 14 and 15 that fall outside the scope of the present invention are found to be about 40% shorter than the examples of the present invention, with the continuous molding time being 27 hours (hr) and 29 hours (hr). . All of these abnormalities are scratches on the extruded material 6, and cracks, breakage, peeling, etc. of the hot extrusion die 1 are not observed at that time, but the decrease in strength, hardness, and toughness at high temperatures has an effect. This is because the inner peripheral surface lb of the through hole la, which is the guiding portion, has deteriorated. In addition, the overall evaluation was acceptable because continuous molding for at least one day was possible.

[0094] Further, Comparative Sample No. 16, in which the body of the hot extrusion die 101 was made of a zircoure-based ceramic, had a continuous molding time of only 5 hours (hr). This is because the inter-extrusion die 101 is damaged. As a result, zirconia ceramics have the advantage of having a smooth surface and high slidability. However, the high-temperature strength due to the increase in monotly (monoclinic phase) is low, and as a material for hot extrusion dies, The overall rating was X, not appropriate.

[0095] Furthermore, the sample No. of the comparative example in which the main body of the hot extrusion die 101 is an SKD material, and the cermet made of NiCrZCr C ZNbC is thickened on the inner peripheral surface 101b of the through hole 101a of the extruded material 6.

3 2

In No. 17, an abnormal flaw occurred in the extruded material 6 when the continuous molding time was 18 hours (hr), and the cause was peeling of the reinforced portion 7 of the inner peripheral surface 101b. Peeling of the reinforcing portion 7, the difference in the thermal expansion coefficient of the SKD61 material and NiCrZCr C ZNbC cermet materials, about 6 X 10- ⁶

3 2

It seems that big is a big factor. Further, even if the exfoliation does not occur, the NiCrZ Cr C ZNbC cermet is composed of a carbide cermet.

3 2

It is more susceptible to degradation by acid in high temperature environments than TiCN cermets.

[0096] From the above results, when the hot extrusion die 1 made of TiCN cermet material of the present invention is used for hot extrusion of aluminum alloy or the like, conventional carbide, SKD61, zirconia ceramics It can be seen that a life expectancy of at least 1 to 2 days or more can be expected when compared with those made of cermet and carbide cermet. [0097] [Example 3]

Form an amorphous film lc on the inner peripheral surface lb of the through-hole la of the hot extrusion die 1 of the present invention and form an amorphous film lc with alumina or a silicon carnoid. In this case, the effect on the continuous molding time in a high temperature environment when the thickness t was produced in the range of 0.1 to 1.5 m was confirmed.

[0098] The sintered body to be the hot extrusion die 1 was the same in composition and shape as the sample No. 12 in Example 2. Then, an amorphous film lc of alumina and silicon carbide is formed on the inner peripheral surface lb of the through hole la shown in FIG. 1, and the thickness t is set to 0.1, 0.2, 0.5, 1.0, 1 2 and 1.5 m, each of which was made into one of 6 levels, was attached to a hot extrusion molding machine 11 and after lhr preheating, aluminum alloy extruded material 6 was continuously formed at a speed of 30 mZmin. did. Incidentally, the sample in which the amorphous film lc was not formed was Sample No. 12 of Example 2 and compared based on this.

[0099] Here, the preheating temperature of Sample No. 12 where the amorphous film lc is not formed on the inner peripheral surface lb of the through hole la is 500 ° C for 1 hour (hr), and the forming temperature of the aluminum alloy is 460 ° C. When the amorphous film lc was alumina, the preheating temperature was 550 ° C and the molding temperature was 480 ° C. When the amorphous film lc was silicon carbide, the preheating temperature was 500 ° C. and the molding temperature was 460 ° C. Conventionally, the preheating temperature is generally lower than the molding temperature, in order to prevent deterioration of the inner peripheral surface of the through-hole due to oxidation during preheating. However, since it is originally preheating to maintain the dimensional accuracy and surface quality of the extruded material 6 immediately after the start of molding, it is desirable to set the preheating temperature to be equal to or higher than the molding temperature. In this example, the preheating temperature was set higher than the molding temperature.

[0100] The method for forming the amorphous film lc of alumina and silicon carbide was a sputtering method, and the condition was 250 ° C.

[0101] The amorphous film lc is made of alumina and has a thickness t of 0.1, 0.2, 0.5, 1.0, 1.2, 1.5 m. It was set as sample Nos. 21 to 26 in the examples.

[0102] The material of the amorphous film lc is silicon carbide, and the thickness t is 0.1, 0.

2, 0.5, 1.0, 1. 2, 1.5 / zm Force of execution of the present invention Sample No. 27 to 32 in row f It was.

[0103] Then, as described above, after predetermined preheating, continuous forming of the aluminum alloy was performed, and the surface of the extruded material 6 had a scratch depth of 10 μm and a width of 20 μm or more. The continuous molding time at the time was measured. As in Example 2, the comprehensive evaluation cannot be used when the continuous molding time is less than 24 hours (hr) (X), 24 hours (hr) or more, and less than 36 hours (hr). Good (Δ), 36 hours (hr) or more, less than 48 hours (hr) as good (◯), and more than 48 hours (hr) as good (（).

[0104] Table 3 shows the above results.

Incidentally, the results of TG-DTA differential thermal analysis of the die 1 for hot extrusion molding of the TiCN cermet material of the present invention are shown in FIGS. Fig. 6 is an analysis chart of TiCN cermet without an amorphous film lc formed on the inner peripheral surface lb of the through hole la, and Fig. 7 is an analysis of an alumina amorphous film lc formed on the inner peripheral surface lb of the through hole la. FIG. 8 is an analysis chart of the silicon carbide amorphous film lc formed on the inner peripheral surface lb of the through hole la.

[0106] For the TG-DTA differential thermal analysis, an SSC5000 differential thermal analyzer manufactured by Seiko Denshi Kogyo Co., Ltd. was used.

[Table 3]

*: Of

[0107] As can be seen from the results in Table 3, compared with Sample No. 12 in which the amorphous film lc was not formed on the inner peripheral surface lb of the through hole la of the extruded material 6 of the hot extrusion die 1 It can be seen that in the case where the amorphous film lc is formed, the continuous molding time is improved by about 25 to 80%.

[0108] Samples Nos. 21 to 26 in which the amorphous film lc was formed of alumina were continuously formed even though the preheating temperature was 50 ° C higher than that of silicon carbide samples Nos. 27 to 32. Time has improved by about 10%. Therefore, in the hot extrusion molding of aluminum alloys and the like performed at a preheating temperature and a molding temperature of about 400 to 600 ° C., an amorphous amorphous film lc in a relatively high temperature region, and a silicon force-bid amorphous in a low temperature region. It is preferable to use a hot extrusion die 1 on which a film lc is formed.

[0109] The relationship between the thickness t of the amorphous film lc and the continuous molding time is as follows. Samples Nos. 21, 22, and 23 of the amorphous film lc of alumina and Samples Nos. 27, 28, and 23 of the amorphous film lc of silicon carbide As can be seen from Fig. 29, the continuous molding time is improved as the thickness t force becomes SO. 1, 0.2, 0.5 m. In particular, in Sample Nos. 22 to 26 where the thickness t of the amorphous film lc of alumina is 0 or more, the continuous molding time is improved by about 55% or more compared to Sample No. 12 where the amorphous film lc is not formed. Thus, sample Nos. 22 to 26 of the examples of the present invention can be continuously molded for about 3 to 3.5 days, and the conventional hot die or SKD61 material die 101 for hot extrusion molding can be used. This is a remarkable effect compared to the generally-mentioned half-life.

[0110] However, sample Nos. 21 and 27 with an amorphous film lc thickness t of 0.1 μm improved the continuous forming time compared with the case where the amorphous film lc was not formed, but the effect was less. Is too thin, the surface force during preheating is thought to be due to the start of acidification.

[0111] In addition, Sample Nos. 26 and 32, in which the thickness t of the amorphous film lc is 1.5 μm, have a shorter continuous molding time than when the thickness t is 1.0 and 1.2 m. I understand. The reason for this is presumed to be due to acidification due to slight peeling of the amorphous film lc. If this thickness t is made thick, for example, about 2 m or more, it will not be described in this example, but it will be easy to cause contact with objects when setting the hot extrusion die 1 etc. A Considering that the morphous film lc may be peeled off and only the formation time of the amorphous film lc by sputtering is increased, the thickness t of the amorphous film lc is preferably 0.2 to 1.2 / zm. Yes, more preferably 0.5 to 1.2 m.

[0112] Then, as can be seen from the TG-DTA differential thermal analysis charts shown in Figs. 6, 7, and 8, the acid-oxidation reaction of the TiCN cermet material used in the hot extrusion die 1 of the present invention is About 550. The results showed that the acid-acid reaction of C and alumina amorphous film lc was 600 ° C or higher, and that of silicon carbide amorphous film lc was 600 ° C or higher.

[0113] In the TG-DTA differential thermal analysis chart shown in FIG. 6, it can be confirmed that the oxidation reaction starts at about 550 ° C. Therefore, the hot extrusion die 1 of the present invention has a through-hole in the extruded material 6. Even if an amorphous film 1c is formed on the inner peripheral surface lb of 1a, even if the preheating temperature is set to around 500 ° C, there is no fear of deterioration. Furthermore, when the amorphous or silicon carnoid amorphous film lc is formed, there is no risk of deterioration of the inner peripheral surface lb of the through-hole la due to thermal oxidation even if the preheating temperature is increased to about 600 ° C. Wow.

[0114] Thus, when the hot extrusion die 1 of the present invention is used for hot extrusion molding, it is not necessary to limit the preheating temperature to a temperature lower than the molding temperature as in the conventional case. As a result, it is possible to obtain a product with stable dimensions and surface quality immediately after the start of molding of the extruded material 6 and to significantly improve the continuous molding time.

[0115] The critical significance of each yarn is described below.

[0116] Table 4 shows the critical significance of the composition of TiCN, Ti, TiC, and TiN.

[Table 4]

Here, as an evaluation of slidability, a test was conducted to compare the extrusion speed with a conventional die. I

[0118] Note that Sample No. 43 did not satisfy the sinterability, and thus was unable to be produced.

[0119] When there is more TiCN, the slidability is higher, and TiCN TiN, TiN, and TiC, which are decomposition products of TiCN, should not exceed the upper limit. If Ti, TiN, and TiC are not contained to some extent as impurities, TiCN will locally crystallize, and the die surface will become unstable.

[0120] Table 5 shows the critical significance of the TaC composition.

[Table 5]

[] Y (ppy0121) φxra Photoelectron sectroscol

Note) However, the movement decreases.

The surface area ratio was compared by analysis.

[0122] The more TaC is, the higher the acid resistance is, but if the upper limit is exceeded, the slidability tends to deteriorate and the die cannot be used.

[0123] Table 6 shows the critical significance of the composition of Ni and Cr.

[Table 6]

1 and below. Note 2) However, if the wear resistance is reduced

[0124] Here, as an evaluation of the denseness, the relative density (according to Archimedes method), that is, the ratio to the ideal density was evaluated.

[0125] When appropriate amounts of Ni and Cr are included, the density is close to the ideal density, but when the upper limit is exceeded, the wear resistance tends to decrease, and when the lower limit is exceeded, the sinterability tends to decrease.

[0126] Next, Table 7 shows the critical significance of the particle size range and weight ratio for the two peaks in the particle size distribution of the sintered body of the present invention.

[Table 7]

[0127] Here, tests for evaluating sliding properties and TiCN decomposability were performed.

The sintered bodies to be evaluated were those having the same composition as Sample No. 1 in Example 1, and were prepared by adjusting the same method as above. Sample Nos. 62 to 73 with two different peaks in the particle size distribution were obtained. Was used. Sample Nos. 74 to 78 are obtained by changing the ratio of crystal grains of the two peaks.

Evaluation was performed about the toughness, strength, and slidability of the sintered body. Standard value of the toughness is more than 10 MPa'm ^V2, the 10MPa'm ^1/2 or good (〇) was 7MPa'm ^1/2 or more 10MPa'm ^1/2 less than the usable (△). The standard value of strength is 1150 MPa or more, 1150 MPa or more is good (◯), lOOOMPa or more and less than 1150 MPa is usable (△). With regard to slidability, it was determined that the aluminum material was not damaged by the presence or absence of scratches 24 hours after the aluminum material was actually extruded. .

[0128] As shown in Table 7, when the particle size range and the ratio for the two peaks in the particle size distribution of the sintered body of the present invention are within the range of the present invention, TiCN does not decompose and slidability Was shown to be good.

If one peak in the particle size distribution is smaller than the lower limit of the range of the present invention, the particle size distribution becomes too weak and the strength deteriorates due to degranulation. 'Toughness tends to be low.

In addition, if the other peak in the particle size distribution is smaller than the lower limit of the range of the present invention, this is because if the particle size distribution is too weak, TiCN will be easily decomposed, resulting in poor slidability and larger than the upper limit. Since the effect of coarse particles is likely to occur, the strength is deteriorated.

When the ratio of the crystal grains of the two peaks is smaller than the lower limit value of the range of the present invention, the strength is deteriorated. When the ratio is larger than the upper limit value, the slidability is deteriorated. This is because if the ratio is small, the effect of degranulation is likely to occur, and if the ratio is large, TiCN is likely to be decomposed.

[0129] FIG. 10 is a diagram showing the composition of Ti, TiC, and TiN of the hot extrusion die of the present invention. For convenience, each vertex of Ti, TiC, and TiN is 3%.

[0130] The hexagonal shaded portion indicated as "CL1" is a range related to Ti, TiC, and TiN in claim 1 of the present application.

Claims

The scope of the claims

[I] TiCN force 8-92.5 mass%, Ti 0.01-1 mass. / ₀ , TiC is 0.01-2 mass. / ₀ , TiN is 0.01 to 2% by mass, and the balance is TaC, Ni, Cr.

[2] The sintered body according to claim 1, having 1 to 11% by mass of TaC.

[3] The sintered body according to claim 1 or 2, comprising 3 to 13% by mass of Ni and 3 to 13% by mass of Cr.

[4] The sintered body according to any one of claims 1 to 3, wherein a particle size distribution of the sintered body has two peaks.

[5] One peak in the particle size distribution is a particle size range of 1.0 to 1.3 μm, the other peak is 1

The sintered body according to claim 4, wherein the sintered body is in a particle size range of 4 to 1.7 m.

[6] In the particle size distribution, the peak in the particle size range of 1.0 to 1.3 m and the peak in the particle size range of 1.4 to 1.7 m are in a ratio of 3: 2 to 1: 1. 6. The sintered body according to claim 5, wherein the sintered body is characterized in that:

7. The sintered body according to any one of claims 1 to 6, wherein crystal grains of the sintered body are spherical.

[8] A sliding member, characterized by being formed using the sintered body according to any one of claims 1 to 7.

[9] A film-forming material, characterized by being formed using the sintered body according to any one of claims 1 to 7.

[10] A hot extrusion die, which is formed using the sintered body according to any one of claims 1 to 7.

[II] The die for hot extrusion molding according to claim 10, wherein the die has a through hole in the vicinity of the center of the plate shape, and an amorphous film is formed at least on the inner peripheral surface of the through hole.

12. The hot extrusion die according to claim 11, wherein the amorphous film is made of alumina or silicon carbide.

[13] The hot extrusion die according to [11], wherein the amorphous film has a thickness of 0.2 to 1.2 m.

[14] The hot extrusion molding die according to any one of claims 10 to 13 is used in a cylindrical die case. It is mounted on one end side, the other end side of the die case is mounted on one end side of a cylindrical container, and an extrusion mechanism for extruding the extruded material is disposed in the container. Inter-extrusion molding equipment.

[15] A hot extrusion molding method using the hot extrusion die according to any one of [10] to [13].

[16] A hot extrusion molding method comprising molding an aluminum alloy using the hot extrusion die according to any one of [10] to [13].

[17] A method for producing a sintered body according to any one of claims 1 to 7, wherein the TiCN powder has an average particle size of 0.3 to 0 and one of the average particle sizes of 1.2 to 2 111. Mix ^^ powder with a weight ratio of 7: 3 to 9: 1, and then add TaC powder with an average particle size of 1.5 μm or less and Ni powder and Cr powder with an average particle size of 2 μm or less. And a method of producing a sintered body, comprising a step of grinding and mixing together with a solvent to form a slurry.