摘要
Chemical vapour deposition (CVD) diamond?coated tools have high hardness, excellent wear resistance, good impact toughness, and chemical stability. These tools can meet the requirements of high efficiency and precision machining. Therefore, this technology has been used as commercial coating tools for light?weight, high?strength, and difficult?to?process materials, such as high?silicon aluminium alloys, carbon fiber?reinforced composite materials and graphite. However, CVD diamond?coated tools based on WC?Co cemented carbide are prone to peeling off during the cutting process. Therefore, the development of WC?Co cemented carbide / CVD diamond?coated tools with excellent wear resistance and long?term processing stability is inevitable. Recently, it has been reported that a combination of chemical etching and mechanical treatment can be used to remove the Co binder in the substrate, which enhances the adhesion strength of the diamond coating. Thereby, the bonding performance of WC?Co cemented carbide / CVD diamond?coated tools is improved. However, these techniques lead to the formation of a brittle layer and decreased substrate strength and toughness. A Co?containing compound or deposited intermediate layer, which can successfully block the Co binder, is formed between the WC? Co cemented carbide substrate and diamond?coating to prevent a reduction in substrate strength. Moreover, the tribological properties and adhesion strength of diamond?coated tools were also reported to be improved by adjusting the diamond layer's process parameters and structure and combining microcrystalline and nanocrystalline diamond layers. Firstly, this paper reviews the current applications and existing problems related to WC?Co cemented carbide / CVD diamond?coated cutting tools. Subsequently, the main causes of tool adhesion failure are analysed. Based on the initial review of literature, the latest research progress in the performance improvement of coated tools by various optimisation processes is introduced. Furthermore, this paper presents different grades of WC?Co cemented carbide / CVD diamond?coated tools and the same grades sourced from different manufacturers that were greatly affected by the substrate pretreatment method, such as chemical etching, mechanical etching, the formation of a Co?containing compound or deposited intermediate layer, and the adjustment of the process parameters and structure of the diamond layers. In conclusion, it is proposed that obtaining a universal pretreatment and deposition technology for realising high?efficiency and long?life cutting of WC?Co cemented carbide / CVD diamond? coated tools for different application scenarios may be a future research prospect. ? 2023 Cailiao Daobaoshe/ Materials Review.
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