合金工具鋼ＳＫＤ１１にＣＶＤ処理したＴｉＣ被膜の特性

Abstract

This paper deals with the characteristics of TiC coated on the tool steel of SKD11 by CVD method. The surface residual stress was measured by the X-ray stress measuring method. Also the characteristics of adhesion by the scratch test and wear resistance by the wear test were evaluated. Furthermore, the effect of heat treatment (quenched at 1020°Cand then at 450°C or 520°C) after CVD on these characteristics was considered. The results are as follows : (1) The residual stresses of TiC layer are compressive. However there is difference in values between after quenching and after tempering, and further there is also difference in values between in case of tempering at 450°C and tempering at 520°C. The stresses were -3.17GPa and -2.94GPa, respectively. These values were nearly equivalent to the calculated values of thermal stress. (2) Acoustic emission signal was detected corresponding with peeling off or damage of TiC layer. Also the critical load is subjected to the influence of substrate. The harder the substrate, the larger the critical load. (3) Wear resistance of SKD11 is extremely improved by means of coating CVD-TiC. When OHGOSHI type wear test is applied and TiC layer is very thin, not only the wear resistance of TiC layer but also the substrate of SKD11 is evaluated.