材料动态性能对高速切削切屑形成的影响规律

Effect of material dynamic properties on the chip formation mechanism during high speed machining

高速切削作为一门先进制造技术已经在工业生产中得到日益广泛的应用,对高速切削过程切屑形成机理的研究有助于进一步发挥高速切削技术的优势和促进高速加工装备的发展,同时可指导优化切削参数、控制切屑形态以改善加工表面质量.高速切削切屑形态变化是工件材料在不同切削载荷下表现出的动态力学性能差异所致.弄清楚高应变率下材料动态力学性能有利于揭示高速切削切屑变形与失效机理,同时高速切削实验的合理设计与应用可以成为材料在高应变率下动态力学性能的新型测试手段.本文以高速切削过程工件材料动态性能变化对切屑形成的影响为主线,结合我们在高速切削切屑形成机理方面多年的研究成果,对高速切削过程中工件材料的强度、塑脆性和微观组织变化等方面进行了综述分析.阐明了高速切削条件下碎断切屑形成的力学条件,指出了传统切削理论在应力状态对切屑变形和失效的影响机理、切屑微观组织演化等方面研究存在的不足,最后对未来的超高速切削切屑形成机理研究进行了展望.

As an advanced manufacturing technology, high speed machining has been widely used in industries. Research on chip formation mechanism during high speed metal cutting plays vital role in further development of its disvantages and innovation of the machining equipment, and it can help to instruct the optimization of cutting parameters to control the chip morphology and improve the finished surface quality. The essence of chip morphology variation during high speed machining is determined by the material dynamic properties under different cuttig loads. Understanding the material dynamic properties under high strain rate is beneficial to reveal the chip deformation and failure mechanism during high speed machining. Meanwhile, reasonable design and application of high speed cutting experiments can be used as new test method of material dynamic properties. Based on the effect of material dynamic properties on the chip formaion process, this paper summarize the variation of material strength, brittle and ductile properties and microstructure combined with our research findings on chip formation mechanism in recent years.The mechanical conditions of fragmented chip formation under ultra high cutting speed is presented. The deficiency of traditional cutting theory are indicated in such aspects as the effect of stress state on chip deforamon and failure mechaism, and chip microstructure evolution, etc. In the end, the research tendency on chip formation mechanism during ultra high speed machining in the future is outlooked.