AlTiCrN涂层结合界面组织特征与结合性能

以Ti、Al和Cr为靶材,采用阴极离子镀在YT14硬质合金刀具表面制备一层AlTiCrN涂层,通过扫描电镜、能谱仪和X射线衍射仪分析了其表面和界面形貌、化学元素组成和物相,并用线扫描和面扫描研究了涂层中化学元素在结合界面处扩散机理.用划痕法表征其界面层结合强度,对界面结合机理进行了讨论.AlTiCrN涂层的物相主要以AlN、CrN和TiN为主,涂层在(111)晶面具有很强的择优取向.涂层中Al、Ti、Cr和N原子数分数高于基体,在结合界面处呈阶梯状过渡分布,基体中C原子扩散进入TiN、AlN和CrN晶格点阵中,形成明显的扩散层.涂层结合界面为机械+扩散形式,其结合方式主要是由吸附结合、扩散结合和化合结合方式组成.划痕过程中涂层经历弹性变形、塑性变形和涂层剥离三个阶段,界面结合强度为59.2N. 

Interfacial structural characteristics and bonding performance of AlTiCrN coatings

A layer of AlTiCrN coating was prepared on the YT14 hard alloy cutter surface by cathodic arc ion plating(CAIP) with Ti,Al and Cr targets. The morphologies,chemical elements and phases of the coating surface and interface were observed by means of scanning electron microscopy(SEM),energy dispersive spectrometer(EDS) and X-ray diffraction(XRD),respectively. The diffusion mechanism of chemical elements at the interface was analyzed by line scan and plane scan. The bonding strength of the interface was characterized by scratch test,and the binding mechanism was discussed. The results show that phases in the coating mainly are composed of AlN,CrN and TiN,and the crystal plane of(111) has a strong preferred orientation. The concentrations of Al,Ti,Cr and N in the coating are higher than those in the substrate,showing a step-like distribution at the interface. C atoms in the substrate diffuse into the TiN,AlN and CrN lattices to form an obvious diffusion layer. The interface is a mechanical and diffusion form,mainly combined with adsorption bonding,diffusion bonding and chemical combination. The coating bears three stages in scratch process,i. e.,elastic deformation,plastic deformation and coating stripping,and the interface bonding strength is 59.2 N.