The wear-resisting property of the mold can be significantly improved by depositing HFCVD diamond film on the surface of the inner bore of the traditional cemented carbide drawing mold,and the application effect can be improved as friction coefficient during the drawing process being reduced.However,with regard to small-aperture wire drawing mold,there is an extremely high requirement for alignment of the hot filament when depositing diamond film on its inner bore surface through HFCVD method.Meanwhile,the two essential conditions-"filament temperature as high as possible" and "substrate temperature being controlled within appropriate range"-are hard to be satisfied simultaneously.Parallelogram wire drawing device that can ensure the alignment of the hot filament and auxiliary heat radiating clamping fixture that can meet the double temperature requirement of the inner bore surfaces of hot filament and wire drawing mold have been developed and introduced in this article.Enameled wire drawing mold of a diameter of 1.3 mm was selected as the study subject.Technological parameters related to the temperature of the inner bore surface of the wire drawing mold during the deposition process of diamond film coating have been optimized through computational fluid dynamics simulation method and orthogonal preparation method based on the finite volume method.Based on that,high quality BDM-UM-UNCCD (boron-doped micro-crystalline,undoped micro-crystalline and undoped nano-crystalline composite diamond) film with exellent comprehensive performance which can meet the requirement of high speed drawing production of the high quality enamelled wire is uniformly deposited on the inner bore surface of the wire drawing mold.As a result,the service life of the mold has been significantly improved and an exellent application effect has been achieved.%在传统的硬质合金拉拔模具内孔表面沉积热丝化学气相沉积(Hot filament chemical vapor deposition,HFCVD)金刚石薄膜可显著提升模具的耐磨损性能,降低拉拔过程中的摩擦系数,改善模具应用效果,但是对于小孔径拉丝模而言,采用HFCVD方法在其内孔表面沉积金刚石薄膜对热丝的对中性提出了极高要求,且难以同时满足"热丝温度尽量高"和"基体温度控制在合适的范围内"这两个必要条件.文章开发了可保证热丝对中性的平行四边形拉丝装置及可满足热丝及拉丝模内孔表面双重温度要求的辅助散热装夹夹具,并选取定径带直径为1.3 mm的漆包线拉丝模作为研究对象,结合基于有限体积法的计算流体动力学仿真方法和正交配制方法,对该工况下内孔金刚石薄膜涂层沉积过程中与拉丝模内孔表面温度场分布相关的工艺参数进行了仿真优化,在此基础上,在拉丝模内孔表面均匀沉积了可满足高品质漆包线高速拉拔生产需求的、具有良好综合性能的高质量硼掺杂微米-未掺杂微米-未掺杂纳米复合金刚石(boron-doped micro-crystalline,undoped micro-crystalline and undoped nano-crystalline composite diamond,BDM-UM-UNCCD)薄膜,显著提高了模具寿命,获得了良好的应用效果.
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