基片温度对硬质薄膜残余应力沿层深分布影响的研究

This study will focus on the TiN films deposited by magnetron sputtering and multi arc ion plating on 304 stainless steel and investigate the relationships among substrate temperature during depositing films, microstructures and residual stresses of the films. The residual stresses include the average stress in the whole film and the stress distribution along film thickness. The experiments to control substrate temperature during depositing films will be used to clarify the above relationships. The following results will be achieved:① The effect mechanism of grain size of films on their residual stresses; ② The effects of crystallization of amorphous films on their residual stresses; ③ A new method to prepare hard films will be put forward - first, the whole amorphous film deposited on substrate; second, the whole film crystallized by annealing treatment; ④ The technology parameters of the method will be investigated for preparing the hard films with the appropriate residual compressive stresses in the whole film and with the even stress distribution along film thickness. The research results not only help understand the residual stresses and their distribution along thickness in hard films, but also help design the preparation technology of hard films with appropriate residual compressive stresses.

以磁控溅射和多弧离子镀制备的TiN/304不锈钢膜基系统作研究对象，探究沉积硬质薄膜时的基片温度与膜的微观组织和膜的残余应力三者之间的关系。这里的残余应力包括全膜厚平均值和它沿薄膜厚度方向的分布两个内容。为进行此项研究，设计了一种在沉积薄膜的过程中控制基片温度的试验方法。通过试验将获得以下成果：①薄膜晶粒尺寸对其残余应力的影响机制；②非晶薄膜晶化过程对其残余应力的影响；③提出一种制备硬质膜的新方法——第一步在基片上沉积出全为非晶态的薄膜，第二步通过退火处理使整个薄膜都转变为结晶态；④探索此新方法的工艺条件，使制备出的硬质膜具有适中的全膜厚平均残余压应力，且压应力在膜厚度方向上均匀分布。研究成果不仅有助于深化对于硬质膜的残余应力及其沿膜厚分布的认识，而且有助于设计出可制备带有适当残余压应力的硬质薄膜。

薄膜制备技术和膜基结构特点，决定了其很难消除残余应力。适当的残余压应力有利于薄膜的力学性能，而过高的残余应力，将导致薄膜的变形、断裂、分层，甚至脱落。对于硬质薄膜，其残余应力通常较大，所带来的问题更加突出。本项目以典型的硬质薄膜TiN和TiAlN薄膜为研究对象，通过控制基片温度，调节薄膜生长时的能量状态，对薄膜的残余应力与其微观结构进行了系统研究。提出了一种有效调节薄膜应力的新方法—在控制基体温度的条件下，采用电弧离子镀和磁控溅射复合工艺，可有效调节薄膜残余应力。本项目在研究过程中，还取得了如下结果：①薄膜厚度增大时，由残余应力引起的膜基界面剪切力显著增大，这是导致大厚度薄膜难以制备、容易脱落失效的重要原因；②TiAlN薄膜中,随着Al含量增加，薄膜应力先增大后减小；③采用逐渐增加氮气流量的方式,可有效改善薄膜应力沿层深分布,制备大厚度硬质薄膜，；④在控制基片温度的条件下，使用电弧离子镀和磁控溅射复合工艺，可以有效调节薄膜的残余应力及其沿层深分布；⑤轴向磁场增强技术有利于TiN/Cu纳米复合薄膜的制备。本项目的研究成果，不仅使我们对薄膜应力及其沿层深分布规律有了更深入的理解，还使我们找到了一种优化硬质薄膜力学性能的新方法。