微米、纳米及微/纳米复合金刚石涂层的切削性能研究

摘要

Chemical vapor deposition method was used to deposit micro-,nano-,and micro∕nano-diamond coatings on cemented carbide substrates,and then the cutting properties were tested.Based on the machined surface roughness and flank and rake wear of diamond coated tools,cutting properties of different diamond coatings were analyzed and failure forms and mechanisms were summarized.The results showed that the roughness of the surface machined with nano diamond coated tools was the smallest(R a =0.942 μm) and that the roughness of the surface machined with micro diamond coated tools was the biggest (R a = 1.631 μm).It was also showed that nano diamond coated tools had the largest flank wear,land width of which was about 2 times and 5 times larger than those of micro diamond coated tools and micro∕nano diamond coated tools respectively.In addition,the interfacial adhesion strength of micro∕nano diamond coating was better,so the diamond film did not exfoliate and wore less.The main failure form of diamond film coated tools was coating premature exfoliation,and the failure mechanism was mainly due to big residual stress,low chemical purity,severe internal cracks,high surface roughness and high cutting force,as well as the built-up edge.%利用化学气相沉积(chemical vapor deposition,CVD)法在硬质合金上制备纳米、微米以及微/纳米复合金刚石涂层,并进行了切削对比试验。通过测试已加工材料的表面粗糙度和金刚石涂层刀具前、后刀面磨损,对比分析了不同金刚石涂层的切削性能,同时总结了 CVD 金刚石涂层刀具的失效形式及机理。结果表明：纳米金刚石涂层刀具切削加工后的表面粗糙度值最小,R a =0.942μm；微米金刚石涂层刀具切削加工表面粗糙度值最大,R a =1.631μm；纳米涂层刀具的后刀面磨损最大,约为微米涂层的2倍,复合涂层的5倍；微/纳米复合金刚石涂层刀具膜/基结合力高,前、后刀面的金刚石涂层没有出现脱落,且刀具的磨损量较少；金刚石涂层刀具的主要失效形式是涂层的过早脱落,其失效主要是由金刚石涂层的残余应力大、涂层化学纯度低、内部产生微裂纹多,以及切削时表面粗糙度高、切削力大和刀具积屑瘤普遍等原因引起的。