Developing and Evaluating the Performance of Electroplated Diamond Tools for Drilling and Milling Hart-To-Cut Materials

In this two-year project, electroplated diamond tools will be fabricated for drilling and milling hard-to-cut materials of SiC, Inconel 718, and carbon fiber plates. Under financial support from MOST, electroplated diamond tools with a distribution of multi-layer diamonds were successfully developed by the project applicant and were successfully used for drilling and milling the Al2O3 plates. During machining with electroplated Ni-diamond tools, we found that the cutting ability of an electroplated Ni-diamond tool significantly reduced because of embedding the diamond particles into the Ni substrate. Therefore, the substrate with a high hardness and anti-thermal softening is required for electroplated diamond tools. We have developed suitable electroplated substrates of anneal-hardened Cr-C (~1500 Hv) and high-hardness Ni (1000 Hv) deposits, respectively, with them electroplated diamond drillers and millers with a distribution of multi-layer diamonds were fabricated. In the first year, electroplated diamond tools with a tool substrate made of round medium carbon steel were prepared for drilling and milling SiC plates with an extreme high hardness. Experimental results will be compared with machining Al2O3 plates. During the first year, Inconel 718 plates with high ductile property are used for drilling and milling with electroplated diamond tools. Owing to having continuous chips, the drill bit should be redesigned to have a drill belly for smooth throwing chips during drilling. Thus, the drill bits will be in a plate from with which the drilling ability will be compared with that drilled with hallow drill bit. In the second year, the electroplated diamond tools will be use to machine carbon fiber plates which have an extreme high hardness and high ductility. The drilling ability of drill bits in hallow and plate forms will be evaluated. The drilling force will be measured with dynamometer equipped in a milling machine. The milling ability of an electroplated diamond miller will be evaluated by milling distance in a constant depth. Failure of electroplated diamond tools will be studied by means of metallographic and fractographic examination; meanwhile, the failure modes of electroplated diamond tools will be discussed with tool-fabricating methods. It can be expected suitable electroplated diamond tools for hard-to-cut materials can be made after performance this two-year project. Research results will be published at least one articles in SCI journals per year, and applied at least one innovation patent.

Project ID:PB10607-0756
External Project ID:MOST106-2221-E182-022