The Open Mechanical Engineering Journal
2017, 11 : 25-36Published online 2017 June 30. DOI: 10.2174/1874155X01711010025
Publisher ID: TOMEJ-11-25
RESEARCH ARTICLE
Drilling Mechanism Investigation on SiC Ceramic Using Diamond Bits
* Address correspondence to this author at the Department of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang, China; Tel: +86 18651405721; E-mail: gaochaozibo@qq.com
ABSTRACT
Background:
SiC ceramic have been widely used in the fields of armor protection, but SiC ceramic is one of the difficult-to-machine material for its high hardness and low fracture toughness.
Objective:
This paper presents an investigation of drilling mechanism on SiC ceramic using diamond bits.
Method:
Based on the theory of indentation fracture mechanics model, cutting average load model and cutting average depth model for single particle were established, theory analysis of drilling mechanism was carried out; through scanning electron microscope (SEM) observation, experimental removal mechanism was discussed.
Results and Conclusions:
The results show that, brittle fracture is the dominant way for SiC ceramic’s removal mechanism, plastic deformation always exists during the drilling process. Brittle fracture includes cleavage fracture, transgranular fracture, intergranular fracture, material peeling off and grain boundary breakage; resintering and recrystallization happen under the joint action of grinding forces and grinding heat in the contact area, where plastic flow characteristics also appear; powdering removal is accompanied by the drilling process; cleavage fracture and transgranular fracture occur on intergranular pores and grain boundary; residual cracks are found in the drilling surface resulted by drilling stress and high temperature.