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 extrusio

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 DEG C, and a hot extrusion molding apparatus using such a die for hot extrusion molding.

Description

Technical field [0001] The present invention relates to a sintered body and a manufacturing method thereof, a sliding member, a film-forming material and a hot extrusion molding die using the sintered body, and a hot extrusion molding device and a hot extrusion molding method using the hot extrusion molding die . Background technique [0002] Historically, when extruding materials are formed by hot extrusion of aluminum alloys, such as Figure 5 and 9 As shown, the through hole 101a, which becomes the guide part of the hot extrusion molding die 101, which constitutes the bearing portion of the die case 102 incorporated into the hot extrusion molding device 111, will be heated to about 400-500 The slab 5 of an aluminum alloy at a temperature of 0° C. is extruded to form an extruded material 6 of a desired shape. [0003] Moreover, as the material of the hot extrusion molding die 101, cemented carbide (hereinafter referred to as superhard) and SKD61 are usually used. Because the su...

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Problems solved by technology

[0018] However, when the inner peripheral portion 101b of the through-hole 101a made of high-speed steel proposed in Patent Documents 1 and 2 is coated with 1 μm of TiC, the thermal expansion coefficient difference between the high-speed steel of the base material and the coated TiC is large. Easy to peel off the coating

In addition, TiC tends to oxidize in an environment above 450°C, so there is a problem of thermal deterioration, that is, TiC, which is a high-hardness material, undergoes a substitution reaction to become TiO with significantly deteriorated hardness. 2

[0019] In addition, Patent Document 3 proposes to coat the inner peripheral surface 101b of the through-hole 101a with a ceramic layer in the range of 2 to 10 μm by electric discharge machining, wherein the thermal expansion coefficient difference between the base material and the coated ceramic layer is large , so the peeling of the coating cannot be avoided

[0020] In addition, in Patent Document 4, the inner peripheral surface 101b of the through-hole 101a of the SKD material is thickened with a carbide-based cermet in the range of 4 to 15 μm in thickness. Among them, the composition of the carbide-based cermet is from Cr 3 C 2 , NbC, WC, TiC, and SiC carbide-based ceramics, choose one or more than two kinds, but any one of the carbide-based ceramics only contains 10 to 30 wt%, even if it is used, it cannot be obtained, for example, as high as aluminum alloy. sliding properties

Therefore, when the aluminum alloy extruded material 6 is formed, the inner peripheral surface 101b of the through-hole 101a used as the induction part is easy to condense aluminum, so that the problem of damage cannot be avoided, and the formed extruded material 6 is damaged due to abrasion. damage and size inaccuracies

[0021] In addition, the main body of the hot extrusion molding die 101 proposed in Patent Document 5 is made of zirconium-based ceramics or silicon nitride ceramics, because of the fact that sufficient high strength to withstand hot extrusion molding of aluminum alloys cannot be obtained. For one reason, the inner peripheral surface 101b of the through-hole 101a cannot be avoided, or the problem of damage to the formed extruded material 6 due to abrasion and inaccurate dimensions cannot be avoided.

[0022] In addition, Patent Document 6 discloses a method for producing a TiCN-TiC-based cermet sintered body as a material suitable for casting materials in molten aluminum. The reason for thermal deterioration, that is, TiC, which is a high-hardness material, undergoes a substitution reaction and becomes TiO with significantly deteriorated hardness. 2 , so it is not suitable as a mold material for hot extrusion molding such as aluminum alloy

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