点击次数：

论文类型：期刊论文

发表时间：2013-09-01

发表刊物：INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY

收录刊物：SCIE、EI、Scopus

卷号：68

期号：5-8

页面范围：1231-1240

ISSN号：0268-3768

关键字：High-speed machining; Adiabatic shear localization fracture; Isolated segment; Blue brittleness; Shear wave

摘要：Adiabatic shear localization fracture (ASLF), which is a catastrophic fracture of the adiabatic shear band (ASB), will occur inevitably with the further increase of cutting speed. High-speed machining experiment of hardened AISI 1045 steel (HRC 45) is carried out by using a PCBN cutter with rake angle -10A degrees at various cutting speeds up to 1,400 m/min and various feeds from 0.2 to 0.4 mm/r. Chip morphology (including discontinuously serrated chip and isolated segments), crack propagation, and blue brittleness effect in isolated segments formation are observed microscopically. Energy convergence in ASB with cutting conditions is calculated. Considering the effect of shear wave on the formation of ASB in high-speed machining, the ASLF theory under triaxial stress state is proposed and compared with the experimental results. The influences of shear band properties and loading conditions on ASLF are also discussed. The energy saturation limit of the shear band can be reasonably estimated by using the ASLF theory, which lays a theoretical and experimental foundation for further prediction study of isolated segments formation in high-speed machining.