Study on Micro Drilling-Rotating Bending Fatigue of Micro Carbide Drills-
In micro drilling, the run-out of drill due to rotational motion error of spindle or eccentric chucking of drill causes machining error and larger radial forces which may break the drill. Furthermore, because the spindle speed is very high, rotating bending fatigue of drill may dominate the tool life. In the previous work, relationship between bending deflection and radial cutting force, and fatigue fracture of drill were investigated theoretically and experimentally. The objective of this paper is to investigate more in detail the relationship between the radial cutting force/deflection of drill and its fatigue life. A series of pseudo rotating bending fatigue tests was performed by using three types of ultrafine grain carbide drill blank with 0.1mm diameter. The main results obtained are as follows, (1) Rotating bending fatigue curve did not depend on cobalt content and tungsten carbide grain size. This differs from the results of conventional cemented carbides. (2) The fatigue fracture surface was dominantly occupied by fast fracture regions.
Micro drilling Carbide drill Rotating bending fatigue Carbide grain size Cobalt content
Boxiao Ma Mitsuyoshi Nomura Takahiro Kawashima Takayuki Shibata Yoshihiko Murakami Masami Masuda Osamu Horiuchi
Dept.of Production Systems Engineering, Toyohashi University of Technology,1-1 Hibarigaoka, Tempaku, Toyohashi, 441-8580 JAPAN
国际会议
第九届加工技术进展国际会议(9th International Conference on Progress of Machining Technology)
昆明
英文
45-48
2009-04-25（万方平台首次上网日期，不代表论文的发表时间）