盐浴镀覆温度对diamond-Cr/Cu复合材料组织性能的影响

Effect of salt bath plating temperature on microstructure and properties of diamond-Cr/Cu composites

采用盐浴镀法在金刚石表面镀覆Cr层,通过调节镀覆温度(750℃~900℃)对镀层厚度实现可控制备。用模压法制备出不同Cr层厚度的金刚石预制坯,通过无压熔渗制备出Diamond-Cr/Cu复合材料。采用SEM、EDS、XRD、激光热导仪等检测和分析不同镀覆温度对Diamond-Cr/Cu复合材料的组织、界面结构、致密度及热导率的影响。研究结果表明:制备出的复合材料随盐浴镀覆温度的提升,界面处的裂纹、孔洞等缺陷不断减少,组织更加致密。复合材料的致密度由93.8%提升到96.0%,界面处EDS扫描显示Cr元素在近金刚石端界面处富集并生成Cr_3C_2及少量的Cr_7C_3。复合材料的热导率呈现先升高后下降的趋势,当镀覆温度为800℃时,复合材料热导率最高可达455 W/(m·K)。

Cr layer was prepared on diamond surface by salt bath plating method,and by means of adjusting plating temperature（ 750 ℃-900 ℃） the controllable coating thickness was realized.Diamond perform with different Cr layer thickness was prepared by moldingpressing process.Diamond-Cr/Cu composites was prepared by pressureless infiltration.The effects of plating temperature on microstructure,interface structure,density and thermal conductivity of the diamond-Cr/Cu composites were discussed by means of SEM,EDS analysis,XRD and laser conductometer.The results show that the interface cracks,pores and other defects in Cr-diamond/copper composites decrease and the structure is more compact with the increasing of plating temperature.The density of the composites also enhance from 93.8% up to 96.0%.EDS scanning at the interface shows that Cr gathers near the side of diamond interface and forms Cr_3C_2 and a small amount of Cr_7C_3.Thermal conductivity of the composites increases first and then decreases.When plating temperature is800 ℃,the maximum thermal conductivity of the composites is up to 455 W/（ m·K）.