Studying mechanism of anisotropic crack generation on C-,R-,A-,and M-planes of sapphire during ultra-precision orthogonal cutting using a visualized slip/fracture activation model  

作　　者：Suk Bum Kwon Sangkee Min 

机构地区：[1]Department of Mechanical Engineering,University of Wisconsin-Madison,1513 University Avenue,Madison,Wisconsin 53706,USA

出　　处：《Nanotechnology and Precision Engineering》2024年第4期47-64,共18页纳米技术与精密工程(英文)

基　　金：supported by the National Science Foundation under Grant No.CMMI-1844821;supported by the NSF through the University of Wisconsin Materials Research Science Center(Grant No.DMR-1720415).

摘　　要：With the growing demand for the fabrication of microminiaturized components,a comprehensive understanding of material removal behavior during ultra-precision cutting has become increasingly significant.Single-crystal sapphire stands out as a promising material for microelectronic components,ultra-precision lenses,and semiconductor structures owing to its exceptional characteristics,such as high hardness,chemical stability,and optical properties.This paper focuses on understanding the mechanism responsible for generating anisotropic crack morphologies along various cutting orientations on four crystal planes(C-,R-,A-,and M-planes)of sapphire during ultra-precision orthogonal cutting.By employing a scanning electric microscope to examine the machined surfaces,the crack morphologies can be categorized into three distinct types on the basis of their distinctive features:layered,sculptured,and lateral.To understand the mechanism determining crack morphology,visualized parameters related to the plastic deformation and cleavage fracture parameters are utilized.These parameters provide insight into both the likelihood and direction of plastic deformation and fracture system activations.Analysis of the results shows that the formation of crack morphology is predominantly influenced by the directionality of crystallographic fracture system activation and by the interplay between fracture and plastic deformation system activations.

关 键 词：Anisotropic behavior Crack morphology Slip/fracture activation model Single-crystal sapphire Ultra-precision machining 

分 类 号：TQ164[化学工程—高温制品工业]