Preparation method for high-viscosity metal cold extrusion forming mold

Abstract

The invention provides a preparation method for a high-viscosity metal cold extrusion forming mold. A diamond-like film layer is prepared on the working face of the mold by adopting the processes of multi-directional forging, high-temperature quenching, tempering and cryogenic treatment and a plasma-enhanced chemical vapor deposition method through numerical control grinding and ultrasonic electrolytic polishing. Multiple control over the shape, the performance and the surface quality of a high-hardness curved-surface mold is achieved, and the technical problems such as mold sticking and pulling damaging in the high-viscosity metal cold extrusion process are effectively solved.

Description

technical field [0001] The invention relates to the technical field of metal plastic forming, in particular to a method for preparing a high-viscosity metal cold extrusion forming die. Background technique [0002] Tantalum material has high density, high dynamic ductility and excellent penetration performance, which can significantly improve the penetration ability and anti-interference ability at high explosion heights. One of the ideal materials for hoods. Overseas broke through the key manufacturing technology of tantalum and tantalum-tungsten alloy high-density liner in the 1990s, and realized engineering applications, such as American SADARM, German SMART, Swedish BONUS, French ACED155 and other warheads; domestic tantalum, tantalum-tungsten alloy The drug-type mask is still in the development stage, and its application has three restrictive aspects: first, the performance of the tantalum material is unstable; second, the key manufacturing technology of the tantalum d...

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Problems solved by technology

According to the analysis of a large number of literatures, the preparation process of tantalum and tantalum alloy drug covers: firstly, the electron beam melting process is used to prepare tantalum and tantalum-tungsten alloy ingots; Coarse solidified structure formed by electron beam smelting; finally, the medicine-shaped cover is prepared by stamping, spinning, swing rolling, cold extrusion and other forming processes. After the body research, it is believed that the conical shell with micro-crystalline structure can be obtained by using the strong spinning forming technology, and the energy-concentrating rod-type penetrating body can be formed under the action of detonation, but the forming process of the penetrating body is unstable. It shows that it is because of uneven structure and poor symmetry (see Romero L A. The instability of rapidly stretching plastic jet [J], J. Appl. Phys., 1999, 65, 3006-3016); Peng Haijian et al. used pendulum rolling forming + CNC turning to manufacture Ta-W alloy thin-walled rotary parts. The metal streamlines are complete and radial, so that the circumferential performance of thin-walled rotary parts is basically the same. The average grain size is 50 μm. (The fine grain is about 10 μm, the coarse grain is about 120 μm, and the surface roughness is Ra3.2-6.4 μm, the size deviation is (0.12-0.35) mm, the processing tool wears seriously, and 6 tools are required to complete a product (see Peng Haijian. Tantalum alloy Rotary rolling forming process of parts[J], Rare Metals, 2009, 8, 597~600)

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