| Summary: | 碩士 === 國立屏東科技大學 === 機械工程系 === 92 === The purposes of the present study are investigated the drilling properties of the Fe-7Al-1.0C-3.0Cr alloy for three kind of heat treatments by using of the HSS and HSS+Co drills. The drilling work are performed under the relief angles being 6~7°, the feed rate being 0.08mm/rev , the chamfer angle being 118~136°, and the rotary cutting speed being 125~320rpm. The major results are described as following: 1. Being on 980℃/30min solution heated treatment(SHT), the hardness of the alloy is in the range of HRc23 to HRc25. And, the hardness of the present alloy being 1050℃/30min SHT or 1050℃/30min SHT + 550℃/6hrs aging, are HRc18~20 and HRc36~38, respectively. 2. Based on the experiments, the drilling work of the present alloy is more difficult than the commercial AISI 304 stainless steel. The drilling properties of the aged specimen will be better than of the as-quenched specimen. Increasing the chamfer angle to 126~130°, will increase the life the HSS or HSS+Co drills. The optimum drilling parameters by using of the HSS or HSS+Co drills are the feed rate =0.08mm, and rotary cutting speed =200~250 rpm. 3. After being 980℃/30min SHT, 1050℃/30min SHT or 1050℃/30min SHT + 550℃/6hrs aging, the surface roughness of the drilling hole are 2.61μm, 1.96μm, and 1.03μm, respectively. And, the expansion of holes will be in the range of 0.02~0.05mm in diameter.
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