碳化钨-钴合金表面钽离子注入的研究

Study on tantalum ion implantation on tungsten carbide–cobalt alloy surface

在真空和通入氮气两种气氛下,通过MEVVA(金属蒸汽真空弧)源离子注入,在WC–Co合金(YG8)表面制备了钽涂层.分别利用光学显微镜、X射线衍射仪(XRD)和电化学极化曲线测量技术对其表面形貌、相结构和耐蚀性进行了表征.结果发现:钽离子注入"修复"了基体表面的缺陷,使其变得平整光滑.在氮气气氛下进行离子注入,除了生成Ta2O5、Ta1.1O1.05和一些碳化物外,还有TaN0.43和W3N4两种氮化物新相.钽离子注入后,YG8合金在3.5%NaCl溶液中的腐蚀速率大幅降低,但随着钽离子注入剂量增大,耐蚀性下降.相比于真空注入环境,氮气氛围下Ta离子注入所得涂层的耐蚀性更好.

Ta coatings were prepared on the surface of WC–Co(YG8)alloy by MEVVA(metal vapor vacuum arc)source ion implantation under vacuum and in nitrogen atmosphere,respectively.The surface morphologies,phase structure,and corrosion resistance of the coatings were characterized by optical microscopy,X-ray diffraction,and electrochemical polarization curve measurement.It was found that the Ta ion implantation not only“repaired”the defects on the surface of substrate,but also made it flat and smooth.Besides Ta2O5,Ta1.1O1.05,and some carbides which were formed after Ta ion implantation under vacuum,two new nitride phases i.e.TaN0.43 and W3N4 were formed in nitrogen atmosphere.The corrosion rate of YG8 alloy in 3.5%NaCl solution was decreased greatly after Ta ion implantation,but the increase of Ta ion dose reduced the corrosion resistance.The Ta coating implanted in nitrogen atmosphere was better than that implanted in vacuum.