磁过滤阴极真空弧技术制备厚且韧TiN涂层

Thick yet tough TiN coatings deposited by filter cathode vacuum arc technology

极端服役条件的出现对涡轮喷气发动机压气机叶片防护涂层提出了越来越高的性能要求,具备厚且韧,同时满足结合力高且耐磨性好的硬质涂层是未来极端服役环境下的潜在涂层.本文利用磁过滤阴极真空弧技术在304L不锈钢基底上成功地沉积了厚且韧的TiN硬质涂层,并利用扫描电子显微镜、X射线衍射仪等对涂层的形貌、结构和性能进行了研究.实验结果表明:沉积过程中,对TiN涂层进行周期性地高能离子轰击处理,能够实现TiN大晶粒抑制,降低涂层内应力,使TiN涂层实现连续生长,涂层的厚度可达到50μm,沉积速率接近0.2μm/min;同时控制N2气流量不变生成稳定的非化学计量TiNx,使TiN涂层具有一定的韧性.制备的TiN涂层属于超硬涂层,硬度和弹性模量最高分别可达到38.24和386.53 GPa;TiN涂层的结合力良好,压痕无剥落形貌和径向裂纹,涂层的韧性优良;TiN涂层的H/E^*和H^3/E^*2值最高可达到0.0989和0.3742;厚且韧的TiN硬质涂层表现出优良的耐磨性,摩擦系数最低为0.26.

There are some high requirements for mechanical property to protective coatings of turbojet engine compressor blades as the appearance of extreme service conditions.The hard coating with high toughness,good adhesion,good wear resistance and excellent load carrying capacity is a potential coating for extreme service conditions in the future.Thick yet tough TiN hard coatings were successfully deposited on 304 L stainless steel substrates by magnetic filtered cathodic vacuum arc technology.The morphology,structure and properties of the coatings were studied by SEM and XRD,etc.The results show that the continuous growth of TiN coatings attributed to periodic high energy ion bombardment which can suppress the large grain size and reduce the internal stress.The thickness of TiN coating can reach to 50μm and the deposition rate was close to 0.2μm/min.At the same time,the stable non stoichiometric TiN0.9 can be formed by controlling the constant N2 flow rate,which can improve the toughness of TiN coatings.All TiN ciatings belong to superhard coating and the max value of hardness and modulus of elasticity were 38.24 GPa and 386.53 GPa respectively.TiN coatings have good adhesion and excellent toughness.The highest H/E^* and H^3/E^*2 rate of TiN coating can reach to0.0989 and 0.3742.Thick yet tough TiN hard coatings have excellent wear resistance with the lowest friction coefficient of 0.26.