| Summary: | 碩士 === 國立高雄第一科技大學 === 機械與自動化工程研究所 === 99 === The titanium carbide (Ti-C) films have excellent properties including resistance to corrosion, low coefficient of friction and wear resistance. In this study, the Ti-C films are deposited on high speed tool steel (SKH51) by the reactive unbalanced magnetron sputtering process. Meanwhile, a gradient interlayer consisted of Ti / TiN/ TiCN between the Ti-C layer and the substrate is prepared to enhance adhesion strength. In experimental design, the L18(21×37) orthogonal array experiments are used to design this experiment for properties of coefficient of friction and indentation level with parameters of cooling time after deposition、substrate bias、 C2H2 flow rate、target current、working distance、rotation speed and bias during ion bombard. Afterward, mechanical properties are observed and discussed. The best mechanical properties are achieved respectively in L18 as Hardness Hv4200、Coefficient of friction 0.13、Wear rate 5.34E-07 mm3*N-1*m-1.
After Taguchi L18 experiment, we use grey theory to combine S/N of coefficient of friction and indentation level for obtaining S/N of both objects. Finally, to perform one by one experiment ,which other parameters is accorded with parameters of muti-objective experiment. Properties of hardness, coefficient of friction, and adhesion was measured.
While C2H2 flow rate is at 20%, the phase couldn’t be identified by JCPD Cards. But it was confirmed as mixed phase of Ti and TiC by TEM. While C2H2 flow rate is at 25%, TiC phase with (111) and (220) planes were found. While C2H2 flow rate is at 30% and 35%,TiC phase with (111), (220) and (200) planes were found. While C2H2 flow rate is at 40%,In addition, TiC phase with (111), (220), (200) and (311) planes were found, C8 phase with (200), (211) and (220)plane were also found.
Via Taguchi experiment, Grey theory and one by one experiment, properties of TiC were promoted to HF1 from HF5 in indentation level. And it keeps the excellent coefficient of friction of 0.15.These experiment are successful to promote properties of adhesion and coefficient of friction.
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