1. 汇报安排
题目：参加CIRP HPC18 国际会议总结报告会
时间：2018年7月6日9:30-10:30
地点：科技园西五楼南楼301会议室
报告人：许祥，何勇
2. 参加国际会议信息
会议名称：8th CIRP Conference on High Performance Cutting
会议日期：June 25-27, 2018
会议地点：Budapest, Hungary
会议简介：The 8th CIRP Conference on High Performance Cutting (HPC 2018) will be held in downtown Budapest, Hungary, where scientists, researchers and industrial partners can present their latest results and the cutting edge technology in the field of machining. The breathtaking venue of the Pesti Vigadó at the Danube bank is a perfect place to continue the tradition of providing an international forum to exchange new ideas in the community of HPC conferences. According to the traditions of HPC conferences, the scientific programme is structured to numerous sections on major and challenging pre-defined topics. These are chaired by well-recognized researchers.
3. 参会论文信息
Title 1: Effect of morphological evolution of serrated chips on surface formation during high speed cutting Ti6Al4V
Author: Xiang Xu, Jun Zhang, Hongguang Liu, Yutong Qi, Zhechao Liu, Wanhua Zhao
Abstract: Ti6Al4V alloys are widely used in aerospace industry due to its excellent mechanical properties, however, serrated chips are easily formed in high speed cutting and have great influence on the surface formation process. In this study, high speed cutting experiments and simulations ranging from 125-750m/min are conducted to explore the characteristics of serrated chips and surface quality. Accordingly, the evolution of serrated chips characteristics and its effect on cutting force and machined surface are discussed. The results show that the inhomogeneous plastic deformation of serrated chips directly causes the cutting forces fluctuation and then leads to the microwaves of machined surface. Furthermore, the surface toughness reaches the highest around 250 m/min and then decrease with the increase of cutting speed, meanwhile, as for the surface defect dimples, their shapes get equiaxed and sizes become small, which shows that the surface quality is improved by increasing the cutting speed. Therefore, surface quality could be controlled by optimizing cutting parameters with better understanding of the influence of chips evolution on machined surface quality.
Title 2: Interfacial effects on the dynamic stresses in high speed cutting of heterogeneous materials
Author: Yong He, Jun Zhang, Yifei Jiang, Zhechao Liu, Yutong Qi, Wanhua Zhao
Abstract: The microstructure of materials has an important effect on the chip formation and fracture process during metal cutting. Its heterogeneity makes the dynamic mechanical response of materials complicated, which would become more notable with the increase of cutting speed. In this paper, a spring-network discrete element model was established to characterize the heterogeneous material for cutting simulation. The dynamic stress propagation was investigated during the cutting tool impacting on the workpiece at high speeds. Voronoi tessellation method was utilized to create polycrystalline structures in the model and the stress distribution was discussed. Compared with the results by the homogeneous model, the distribution of dynamic stress in polycrystalline model is obviously discontinuous. Furthermore, the normal stress and shear stress propagates in the workpiece as longitudinal and transverse stress waves, which are reflected and transmitted at interfaces. The fluctuation of stress triaxiality is more obvious and changes significantly with the increase of cutting speed, which provides an idea for explaining the fracture mode transition of material in high speed cutting process
