基于表面微观形貌的聚晶金刚石脆性去除机理研究  

Study on Brittle Removal Mechanism of Polycrystalline Diamond Based on Surface Micro-morphology

作　　者：李嫚[1] 贾乾忠[1] 张弘弢[1] 董海[1] 

机构地区：[1]大连理工大学机械工程学院,大连116024

出　　处：《机械工程学报》2014年第13期202-206,共5页Journal of Mechanical Engineering

摘　　要：聚晶金刚石(Polycrystalline diamond,PCD)的磨削是PCD刀具制造中的关键环节,磨削参数的变化影响PCD的去除方式,进而决定刀具的切削性能。采用不同的磨削参数加工PCD复合片,并用王水对磨削后的PCD表面进行腐蚀,通过扫描电镜观察并分析腐蚀后的PCD表面微观形貌,研究PCD的脆性去除方式及其与磨削参数之间的关系。根据去除机理不同,将PCD的脆性去除方式分为微细破碎、沿晶破碎、疲劳解理破碎三种;其中微细破碎又可细分为解理微细破碎和脆性微细破碎。作为湿磨初期的主要去除方式,微细破碎可在所有磨削条件下发生;沿晶破碎通常在金刚石磨粒较锋利时发生;疲劳解理破碎易在金刚石磨粒较钝时发生,因而在干磨后期时疲劳解理破碎较严重。Grinding ofpolycrystalline diamond （PCD） is an important process in PCD cutter manufacturing.The grinding parameters can strongly influence the removal form of PCD,and determine the performance of the cutting tool.PCD specimens are ground at different grinding conditions and etched using chlorinators acid afterward.Brittle removal mechanism of polycrystalline diamond （PCD）,as well as its relation with grinding parameters,is investigated by examining the surface features of pre-etched PCD specimens using scanning electron microscopy.Based on different generation mechanisms,the brittle removal forms of PCD can be classified as micro-cracking,grain-boundary cracking and fatigue-cleavage cracking,and in detail,the micro-cracking form includes cleavage micro-cracking and brittle micro-cracking.Micro-cracking which is the main removal form in the initial stage of wet grinding happens under any grinding condition.Grain-boundary cracking happens when wear particles of diamond wheel are sharp.On the contrary,fatigue-cleavage cracking happens when wear particles of diamond wheel are blunt,especially in the later stages of dry grinding.

关 键 词：聚晶金刚石 磨削 去除机理 解理 破碎 

分 类 号：TG580[金属学及工艺—金属切削加工及机床]