聚晶金刚石复合片的电火花线切割精密加工试验

为了提高聚晶金刚石(PCD)刀具的生产效率,改进加工表面质量并减少刃磨余量,利用慢走丝电火花线切割机床(WEDM)对PCD复合片进行了加工工艺试验.对PCD复合片进行了5次切割,并分别测量了每次加工后的表面粗糙度、富钴界面层凹槽深度及宽度和PCD层刃口加工质量.试验结果表明:PCD复合片经慢走丝线切割多次加工,能够得到较好的表面质量,在众多影响因素中金刚石颗粒大小对加工质量影响较大；其中CTH025型号和CTB010型号的最终表面粗糙度分别为Ra=0.85 μm和Ra=0.57 μm,富钴界面层凹槽的深度分别为16.3 μm和5.7 μm,刃口处切口缺陷的尺寸也与金刚石颗粒的尺寸相当.经WEDM加工后的PCD复合片的刃磨余量可控制在4～15 μm左右.

Experiment of WEDM precision machining for polycrystalline diamond compact

In order to improve the production efficiency,surface quality and reduce the grinding margins of Polycrystalline Diamond(PCD) compact cutting tools,a series of experiments of Low-speed Wire Cutting Electric Discharge Machining(LS-WEDM) for a PCD compact were taken.The PCD compact was cut by the WEDM for five times,then the surface roughness of cutting section,the machining quality of cobalt-rich interface layer and the edge of PCD layer were measured and discussed.The results indicate that the PCD compact shows better surface quality in its cutting section after multiple processing by LS-WEDM,and the machining quality is affected by diamond particle sizes greatly.For two kinds of PCD compacts,CTH025 and CTB010,the surface roughness are Ra=0.85 μm and Ra=0.57 μm,and the depths of the grooves of cobalt-rich interface layer are 16.3 μm and 5.7 μm,respectively.The size of the defect in the edge of PCD compact is matched with that of the diamond particle.The minimum grinding margins of PCD cutting tools can be controlled in 4-15 μm after LS-WEDM.