Cubic boron nitride(c-BN) films were deposited on W6Mo5Cr4V2 high speed steel(HSS) substrate implanted with boron ion by RF-magnetron sputtering. The films were analyzed by the bending beam method, scratch test, XPS a...Cubic boron nitride(c-BN) films were deposited on W6Mo5Cr4V2 high speed steel(HSS) substrate implanted with boron ion by RF-magnetron sputtering. The films were analyzed by the bending beam method, scratch test, XPS and AFM. The experimental results show that the implantation of boron atom can reduce the internal stress and improve the adhesion strength of the films. The critical load of scratch test rises to 27.45 N, compared to 1.75 N of c-BN film on the unimplanted HSS. The AFM shows that the surface of the c-BN film on the implanted HSS is low in roughness and small in grain size. Then the composition of the boron implanted layer was analyzed by the XPS. And the influence of the boron implanted layer on the internal stress and adhesion strength of c-BN films were investigated.展开更多
An investigation has been carried out into the effects of chromium and vanadium content on the oxidation rate and on the adhesion of oxide scales grown on three different chemical compositions of high speed steels und...An investigation has been carried out into the effects of chromium and vanadium content on the oxidation rate and on the adhesion of oxide scales grown on three different chemical compositions of high speed steels under dry and wet conditions.The oxidation tests were carried out in a thermobalance at 650℃for up to 14.4 ks.The mass gain of the specimens increased with increasing contents of water vapour. Alloy composition had no effect on the oxidation rate in dry conditions.The'adhesion'of the oxide scale was determined using indentation with a Rockwell C diamond and the pull adhesion test to determine the interfacial toughness and the tensile strength of the oxide metal bond,respectively.Generally,the results of the investigation indicated that oxide adhesion was lowest for the specimens exposed to dry conditions, and that with increasing water vapour content,the scale was more adherent.Indentation test results showed that an increase in the V concentration was deleterious to oxide adhesion in both the dry and wet environments,whereas an increase in the Cr-content had little effect on adhesion.展开更多
高速钢表面类金刚石(diamond-like carbon,DLC)薄膜的沉积效率和膜-基结合力影响其在切削刀具领域的应用。基于空心阴极原理,利用等离子体增强化学气相沉积(plasma-enhanced chemical vapor deposition,PECVD)的方法,在体积比为1∶3的CH...高速钢表面类金刚石(diamond-like carbon,DLC)薄膜的沉积效率和膜-基结合力影响其在切削刀具领域的应用。基于空心阴极原理,利用等离子体增强化学气相沉积(plasma-enhanced chemical vapor deposition,PECVD)的方法,在体积比为1∶3的CH_(4)和C_(2)H_(2)的混合气体中加入N_(2)在高速钢表面制备类金刚石薄膜,研究了N_(2)体积分数对DLC薄膜结合力和耐磨性的影响。结果表明:掺氮可提高DLC薄膜的沉积效率,改善膜结构。随着N_(2)体积分数的增加,DLC薄膜中sp^(3)键含量和摩擦因数均先增大后减小。掺10%体积分数N_(2)的DLC薄膜厚度达1543 nm,膜-基结合力等级从HF4提高到HF2,摩擦因数降至0.139,耐磨性提高。展开更多
基金National Natural Science Foundation ofChina(No.59971065)
文摘Cubic boron nitride(c-BN) films were deposited on W6Mo5Cr4V2 high speed steel(HSS) substrate implanted with boron ion by RF-magnetron sputtering. The films were analyzed by the bending beam method, scratch test, XPS and AFM. The experimental results show that the implantation of boron atom can reduce the internal stress and improve the adhesion strength of the films. The critical load of scratch test rises to 27.45 N, compared to 1.75 N of c-BN film on the unimplanted HSS. The AFM shows that the surface of the c-BN film on the implanted HSS is low in roughness and small in grain size. Then the composition of the boron implanted layer was analyzed by the XPS. And the influence of the boron implanted layer on the internal stress and adhesion strength of c-BN films were investigated.
文摘An investigation has been carried out into the effects of chromium and vanadium content on the oxidation rate and on the adhesion of oxide scales grown on three different chemical compositions of high speed steels under dry and wet conditions.The oxidation tests were carried out in a thermobalance at 650℃for up to 14.4 ks.The mass gain of the specimens increased with increasing contents of water vapour. Alloy composition had no effect on the oxidation rate in dry conditions.The'adhesion'of the oxide scale was determined using indentation with a Rockwell C diamond and the pull adhesion test to determine the interfacial toughness and the tensile strength of the oxide metal bond,respectively.Generally,the results of the investigation indicated that oxide adhesion was lowest for the specimens exposed to dry conditions, and that with increasing water vapour content,the scale was more adherent.Indentation test results showed that an increase in the V concentration was deleterious to oxide adhesion in both the dry and wet environments,whereas an increase in the Cr-content had little effect on adhesion.
