| 摘要 |
PROBLEM TO BE SOLVED: To enhance the bond strength of a film to be applied to a machining tool in film coating technology using a sputtering process to obtain a comparatively smooth film surface. SOLUTION: In performing etching (surface roughening) by applying bias voltage of -200 V to a tool base metal 20 as pre-treatment in coating a hard film using a sputtering process, the bias voltage is periodically applied with a frequency of 250 kHz, and the non-application time (pulse reverse time) of negative voltage per period is set about 500 nsec, whereby the bond strength of a hard film to the tool base metal 20 is improved to attain excellent bond strength as much as critical load of 100 N or higher in a scratch test, so that fall-off due to separation is restrained to obtain durability which is satisfactory in practical use as a cutting tool. COPYRIGHT: (C)2006,JPO&NCIPI
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