Al/Ti摩尔比对(CrTiAl)N硬质膜相结构和硬度的影响

Effect of Al/Ti Molar Ratio on Phase Structure and Hardness of(CrTiAl)N Films

采用多弧离子镀技术,设计沉积工艺和调整阴极弧源靶组合以及对应的弧源电流,制备出以CrN为基形貌和厚度相同、Al/Ti摩尔比不同的系列(CrTiAl)N硬质膜。测试膜的成分、组织形貌、相组成和表面硬度,研究了Al/Ti摩尔比对其相结构和硬度的影响。结果表明:不同Al/Ti摩尔比的(CrTiAl)N膜其相组成相同,都呈现(200)和(111)晶面择优生长。随着膜层的Al/Ti摩尔比从0.38提高到0.85,其硬度表现出规律性的变化。Al/Ti摩尔比为0.49的(CrTiAl)N膜硬度最高(达到HV4200),Al/Ti摩尔比为0.85时硬度降到HV2600。在膜层组织形貌、膜层厚度以及CrN含量基本不变的条件下,Al/Ti摩尔比直接影响膜层的硬度并呈现出非单调关系。在较大的Al/Ti摩尔比范围内(CrTiAl)N膜层的相结构不变,均为置换式面心立方固溶体。优化Al/Ti摩尔比,可使(CrTiAl)N膜的硬度显著高于(CrTi)N膜而具有超硬性。

A series of(CrTiAl)N hard films with the same morphology and thickness but different Al/Ti molar ratio were prepared via multi-arc ion plating technology with desired processing parameters while varying the combination mode of cathode arc source and target. The chemical composition, microstructure, phase constituent and surface hardness of the films were characterized. Meanwhile the effect of Al/Ti molar ratio on the phase structure and hardness of the films were investigated. The results show that:the(CrTiAl)N films with different Al/Ti molar ratios present the same phase constituents with preferred growth orientations(200) and(111). With the increase of Al/Ti molar ratio from 0.38 to 0.85, the hardness of the film shows a regular change. The hardness of(CrTiAl)N films with Al/Ti molar ratio of 0.49 is the highest, reaching HV4200, however when the Al/Ti molar ratio is 0.85, the hardness decreases to HV2600. The Al/Ti molar ratio has a direct effect on the hardness of the film and shows a non-monotonic relationship when the microstructure, thickness and CrN content of the films are basically unchanged. In the larger Al/Ti molar ratio range, the phase structure of(CrTiAl)N films is unchanged and all of them are displacement-centered cubic solid solutions. The hardness of(CrTiAl)N films is significantly higher than that of(CrTiN) films and which can possess super hardness by optimizing the molar ratio of Al/Ti.