基于金刚石热历史的超硬磨具激光增材制造工艺与组织性能优化  

Optimization of Laser Additive Manufacturing Process and Microstructure Properties for Superhard Tools Based on Diamond Thermal History

作　　者：张伟[1] 高远 马青原 彭英博 武玺旺 蓝阳 陈宇轩 陈治强 ZHANG Wei;GAO Yuan;MA Qingyuan;PENG Yingbo;WU Xiwang;LAN Yang;CHEN Yuxuan;CHEN Zhiqiang(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Henan Huanghe Whirlwind Co.,Ltd,Xuchang 461502,China;College of Engineering,Nanjing Agricultural University,Nanjing 210031,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083 [2]河南黄河旋风股份有限公司,河南许昌461502 [3]南京农业大学工学院,江苏南京210031

出　　处：《湖南大学学报（自然科学版）》2024年第4期132-139,共8页Journal of Hunan University:Natural Sciences

基　　金：国家重点研发计划资助项目(2021YFB3701800);国家自然科学基金区域创新发展联合基金项目(U20A20236);湖南省自然科学基金资助项目(2020JJ4738)。

摘　　要：超硬磨具激光增材制造过程中,金刚石极易受到激光直接辐照和高温熔池的影响,出现石墨化等热损伤现象.选取典型的金刚石磨具用金属结合剂CuSn10粉末,采用粉末床熔融(Powder Bed Fusion-laser Beam,PBF-LB)技术制备CuSn10-金刚石复合材料;围绕高能激光束和高温熔池两个影响增材制造过程中金刚石颗粒性能的关键因素,以单颗金刚石颗粒为研究对象,通过有限元模拟分析构建金刚石颗粒的温度场模型,反映了金刚石颗粒在PBF-LB中的热演化过程;阐明了PBF-LB过程金刚石的热损伤机制,发现金刚石发生石墨化转变并不是由激光的直接辐照造成的,而是由高温熔池的热影响导致,CuSn10-金刚石复合材料在PBF-LB过程中石墨化的临界温度为1491.6℃.建立了PBF-LB工艺-金刚石颗粒温度-石墨化程度-摩擦磨损性能的定量关系,发现随着金刚石颗粒温度的增加,其石墨化程度增加,严重损害了复合材料的摩擦磨损性能.In the laser additive manufacturing process of superhard tools,diamonds are highly susceptible to the direct irradiation of laser beams and the influence of high-temperature melt pools,leading to phenomena such as graphitization and other thermal damage.A typical metal bonding agent CuSn10 powder for diamond abrasives is selected,and the Powder Bed Fusion-laser Beam(PBF-LB)technology is used to prepare CuSn10-diamond composites in this study.Focusing on two key factors affecting the performance of diamond particles in the manufacturing process,high-energy laser beams and high-temperature melt pools,individual diamond particles are selected as the research subject.A finite element simulation analysis is conducted to construct a temperature field model of diamond particles,reflecting the thermal evolution process of diamond particles in PBF-LB.The study elucidates the thermal damage mechanism of diamonds during the PBF-LB process,revealing that the graphitization transformation of diamonds is not caused by direct laser irradiation but is induced by the thermal effects of high-temperature melt pools.The critical temperature for graphitization of CuSn10-diamond composite material in the PBF-LB process is 1491.6°C.Furthermore,a quantitative relationship is established among the PBF-LB process-diamond particle temperature-degree of graphitization-frictional wear performance,demonstrating that with the increase of diamond particle temperature,the degree of graphitization increases,seriously damaging the friction and wear performance of the composite material.

关 键 词：激光增材制造 超硬磨具 金刚石 热演化 石墨化 

分 类 号：TQ163[化学工程—高温制品工业] TB33[一般工业技术—材料科学与工程]