Silicon carbide ceramic and method for manufacturing composite drawing mould of diamond

Abstract

The invention relates to a preparation method for silicone carbide ceramics and diamond composite drawing die. The silicone carbide ceramics is taken as a substrate, and the process of conventional diamond coating deposition, plasma polishing, nano diamond coating deposition, and mechanical polishing is repeated for a plurality of times to remove original blister defects on the surface of an inner hole of a ceramic die. During the cycle of CVD diamond deposition and polishing, a conventional diamond coating is integrated with a nano diamond coating, the plasma polishing is integrated with the mechanical polishing, the plasma polishing is inserted between the conventional coating and the nano coating, and consequently the die becomes more adaptive to the mechanical polishing after the growth of the nano coating. The die which can replace a traditional hard alloy product not only can greatly prolong the service life of a traditional die and device, improve production efficiency, remarkably improve the quality of products concerned and effectively save raw material, but also has great significance for the great reduction of tungsten and cobalt consumption and effective solution to the resource crisis faced by the hard alloy industry.

Description

technical field [0001] The invention relates to a preparation method in the technical field of molds, in particular to a method for preparing a chemical vapor deposition (CVD) silicon carbide ceramic and diamond composite drawing mold. Background technique [0002] Drawing dies are usually made of wear-resistant materials, ideally diamond materials, followed by hard alloys to improve the life of the dies and ensure the dimensional accuracy and smoothness of the products. Considering cost and technical factors, most of the current manufacturing drawing dies use cemented carbide in the case of large aperture (d ≥ 5 mm), and diamond (polycrystalline or single crystal) is only used in small aperture occasions (d ≤ 3 mm). Mold, however, the traditional hard alloy mold wears very seriously during drawing and stranding, the working life is short, the accuracy of related products is difficult to guarantee, the surface quality is poor, the consumption of mold is large, especially the...

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Problems solved by technology

[0004] However, unlike cemented carbide materials, ceramic materials are mostly solid-phase sintered. There are a large number of structural defects in crystalline ceramics, which make the material not dense, and there are often many micropores inside. The inherent defects of ceramic materials have a great impact on its physical and mechanical properties, especially on the friction and wear characteristics, which directly affects its performance in the field of tribology instead of cemented carbide as wear-resistant materials.

[0005] After searching the literature of the prior art, it was found that the Chinese patent "Preparation Method of Diamond Composite Coated Drawing Die" (Patent No. ZL01113027.X) proposes to use a large-aperture cemented carbide die as a substrate, and use a chemical vapor phase method on the surface of the inner hole Deposit a layer of conventional diamond and nano-diamond composite coating to make a diamond coating mold, which can increase the working life by 5-10 times, but the invention uses a WC-Co cemented carbide substrate material, composed of tungsten carbide particles and Binder (cobalt, nickel, etc.) The bonding strength with the base material needs to be improved, and the performance of the coating product is discrete, which limits the further improvement of the service life of the diamond composite coating mold. Since the substrate is still cemented carbide, there is also the consumption of tungsten and cobalt resources. and pressure from rising manufacturing costs

In further searches, silicon carbide ceramics and diamond-coated composite molds have not been found

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