钛合金表面低氧压熔结Al-Si涂层及抗氧化能力

采用低氧压高温快速熔结技术在Ti-6Al-4V合金表面成功地制备出抗高温氧化的Al-Si熔结涂层.与Si改性渗涂层相比,这种工艺相对简单,不需要经过长时间的扩散就能形成足够厚度的Al-Si熔结涂层,省时节能,且涂层中抗氧化元素铝、硅的浓度可通过调整粉末的混合比例来进行控制.X射线检测表明涂层主要由Ti₅Si₃和TiAl₃组成.在923K空气中52h循环氧化试验结果表明:低氧压熔结Al-Si涂层在前10h的氧化过程中氧化增重较快,而在随后的氧化过程中氧化增重较为缓慢,而Si改性渗涂层在氧化过程中一直保持着较高的氧化速率.

Low oxygen partial pressure self-fusing Al-Si coating formed on surface of Ti alloy and its oxidation resistance

An Al-Si fusing coating was successfully produced by means of the low oxygen partial pressure high-temperature fusing technique for the improvement of the high-temperature oxidation resistance of Ti-6Al-4V alloy.Unlike the Si-modified aluminide coating,this technique is much effective and cheap without the need for long time diffusion for the formation of the Al-Si fusing coating,and the concentrations of the oxidation-resistant elements,Al and Si,in the coating can be controlled by adjusting powder mixing ratio.Xray diffraction(XRD) shows that the Al-Si fusing coating is mainly composed of Ti5Si3 and TiAl3 phases.Cyclic oxidation tests at 923 K for 52h in air reveals that the mass gains of the low oxygen partial pressure selffusing Al-Si coating(LOPPF) is rapid in the initial 10 h oxidation and keeps slow in the following oxidation;However,for the Si-modified aluminide coating,it keeps a rapid oxidation rate throughout the oxidation time.