溅射靶材对TiAlN涂层形貌、结构和力学性能的影响

Influenceof Target on Microstructures and Mechanical Behavior of TiAlN Coatings

采用粉末冶金和真空熔炼方法制备了原子比为Ti50Al50的合金靶材,利用磁控溅射工艺在同一工艺参数下制备了TiAlN涂层,借助扫描电镜、原子力显微镜、X射线衍射仪、纳米压痕和结合强度实验,研究了溅射靶材对TiAlN涂层的形貌、结构和力学性能的影响。结果表明:粉末靶材中Ti和Al以单质相存在,Ti镶嵌于Al基体周围,熔炼靶材中形成了TiAl和Ti3Al合金化片层组织;由于两种靶材在组织结构和导热性能上的不同导致其溅射产额、靶材温度和溅射金属离子能量等都出现了明显的差异;对涂层的影响表现为,相比于熔炼靶材涂层,粉末靶材涂层的沉积速率高44%,表面粗糙度低24%,涂层表面熔滴数目和尺寸较小;粉末靶材涂层呈现Ti2AlN相等轴晶生长方式,熔炼靶材涂层由于沉积温度较高表现为Ti2AlN相和TiN相,以等轴晶和柱状晶混合生长;相结构的不同导致涂层的硬度和结合强度出现差异,粉末靶材涂层硬度为25.69 GPa,结合强度属于HF-3,熔炼靶材涂层的硬度为28.22 GPa,结合强度属于HF-5。

Two types of TiMalloy targets, Targets A and B, were fabricatedbypowder metallurgy and vacuum smelting, respectively. The TiMN coatings were synthesized by reactive magnetron sputtering of different TiM alloy targets. The coatings were characterized with X-ray diffraction, scanning electron microscopy, atomic force microscopy and conventional mechanical probes. The results show that the target type strongly affects the microstructures, phase structures and mechanical properties of the TiMN coatings. For example, Target-A resulted in 44% higher deposition rate, 24% lower surface roughness, smaller and fewer metallic micro-droplet than Target-B. Deposited with Target-A, the TiMN coatings consisted of stable single-phased columnar Ti2MN grains, while synthesized with target-B, the coatings contained Ti2MN and c-TiN phases. Besides, when it comes to hardness and interfacial adhesion, the smelted target outperforms the ＂powder target＂ possibly because of their differences in texture and thermal conductivity.