发动机用TiAl表面双辉等离子制备W-Mo合金层及其高温氧化行为

目前采用双辉等离子表面合金化技术在TiAl合金表面制备W-Mo涂层的研究不多。通过SEM与XRD等测试手段,研究双辉等离子表面合金化技术在TiAl基体表面制得的W-Mo合金涂层在780℃温度下的氧化行为。研究结果表明:W-Mo改性合金在初期氧化阶段快速氧化增重,经过100 h氧化后,试样增重5.2 mg/cm2,有效改善了TiAl基体的高温抗氧化性能。W-Mo合金涂层对氧气扩散起到阻碍作用,使TiAl基体抗高温氧化性能获得显著提升。氧化处理后合金涂层表面未发生改变,形成了致密、均匀的氧化膜层。TiAl基体经100 h氧化后表面氧化膜主要是一种柱状晶结构,TiAl基体氧化产物包括金红石型TiO2以及刚玉2种成分。

Preparation and High-Temperature Oxidation Behavior of W-Mo Alloy Coating on the Surface of the Engine by Double-Glow Plasma

Double glow plasma surface alloying technique was used to prepare molybdenum tungsten coating on the surface of TiAl matrix, and the oxidation behavior under 780 ℃ was investigated by SEM and XRD test methods. Results showed that the W - Mo modified alloy was oxidized and the weight rapidly increased at the initial oxidation stage. After oxidation for 100 h, the weight gain of the sample was 5.2 mg/cm2, which effectively improved the high - temperature antioxidant performance of the capital matrix. The modified W - Mo layer had an obstructive effect on oxygen diffusion, and therefore, the high temperature oxidation resistance of the capital matrix was significantly improved. After the oxidation treatment, the surface of the alloy coating did not change, forming a dense and uniform oxide film layer. The surface oxidation film on TiAl matrix substrate after oxidation for 100 h had primarily a columnar crystal structure, and TiAl matrix oxidation products were rutile TiO2 and corundum.