纳秒激光加工PDC织构对表面微观组织的影响

Influence of PDC Surface Texturing Using Nanosecond-Laser on the Microstructure

室温大气环境下采用纳秒激光在聚晶金刚石基(PDC)复合片上加工两种不同深度的槽型织构。采用立体显微镜、光干涉轮廓仪、场发射扫描电镜、可见光拉曼光谱仪等手段表征了织构前后表面的形貌、组织结构和碳的键合结构变化。研究结果表明纳秒激光加工时PDC中金刚石相的烧蚀挥发速度比粘结剂Co相快。加工的织构表面发生金刚石相(sp3C-C)向石墨相(sp2C=C)。织构化后的表面呈现富石墨相的疏松结构。织构不同位置处的相转变有差异,这可能与槽型结构的深/宽比、金刚石及石墨相的导热系数差异等有关。

At ambient atmosphere two kinds of groove textures with different depth on the surface of Poly-crystalline Diamond Compacts (PDC) were fabricated by using nanosecond laser. The surface mor-phology, microstructure and bonding structure of carbon were characterized using stereo-optical microscope, light interference profile instrument, field emission scanning electron microscope and Raman spectroscope before and after texturing. It is found that during laser texturing the ablation rate of Co is slower than that of diamond, and a diamond phase on the PDC surface transforms to a graphite phase. After texturing, the PDC surface presents looser and graphite-rich. The transformation extent varies with the location of the texture, which is probably responsible for the geometry of the texture, as well as the thermal conductivity difference between the diamond and graphite.