Ti6Al4V表面磁控溅射NiCoCrAlY涂层的组织及性能

为了提高钛合金的高温抗氧化能力,采用非平衡磁控溅射技术在Ti6Al4V钛合金的表面沉积了NiCoCrAlY涂层,通过SEM,EDS和XRD分析了涂层氧化前后的物相组成和组织形貌。结果表明:长时间沉积后,受基材原始表面状态和涂层择优生长作用的影响,涂层表面有大量微米级的细小颗粒和少量直径约10μm的圆丘形突起;NiCoCrAlY涂层成分与靶材相近。NiCoCrAlY涂层明显提高了钛合金的抗氧化性能,使其氧化增重速率大大降低。经高温氧化后,涂层与基底的界面处Ti,Ni等元素发生互扩散形成过渡层,随氧化时间延长,过渡层逐渐增厚;并且受高温作用,涂层表面化合物相晶态特征有增强的趋势。

Inoxidizability& Microstructures of Original NiCoCrAlY Coating on Ti6Al4V Alloy by Magnetron Sputtering

In order to enhance the titanium alloy's inoxidizability, a NiCoCrAlY coating was synthesized on the Ti6Al4V alloy surface using unbalanced magnetron sputtering technology. The microstructure and phase composition of coating before and after the oxidation were analyzed by SEM, EDS and XRD. The results show that there are a large number of small micron-size particles and a small amount of a diameter of about 10 μm of the dome-shaped protrusions on coating surface which affected by substrates' surface state and the preferential deposition of coatings. The composition of coating is close to target composition. The oxidation experiments show that the NiCoCrAlY coating can improve the Ti alloy's oxidation resistance obviously, and the rate of coating weight gain decreased greatly. After high temperature oxidation, a transition layer is formed through the mutual diffusion of Ti, Ni and other elements in the interface and grow, thicker and thicker along with the oxidation time; In the surface the compounds phase's crystalline character is enhanced by the function of high temperature.