微波热处理制备硅化物涂层及其抗高温氧化性能  

Preparation and high-temperature oxidation resistance of silicide coating by microwave heat treatment

作　　者：张涛[1] 王德仁[1] 何业东[1] 

机构地区：[1]北京科技大学,北京市腐蚀、磨蚀与表面技术重点实验室,北京100083

出　　处：《材料热处理学报》2011年第12期125-131,共7页Transactions of Materials and Heat Treatment

摘　　要：通过微波加热包埋渗法在高铌钛铝合金基体上制备了硅化物涂层,微波加热功率2.6 kW,埋渗时间2 h。利用扫描电镜、能谱分析和X射线衍射等手段研究了氧化前后涂层的表面形貌、截面形貌、涂层中元素分布和物相组成。结果表明:涂层外部主要物相为TiSi2和NbSi2,并有少量的Ti5Si3和Nb5Si3相,厚度约为15μm;内侧涂层有大约15μm的富铝层。1000℃下氧化100 h的氧化动力学测试结果表明:高铌钛铝合金渗硅后的抗高温氧化性能、抗剥落性能有了显著提高,其单位面积增重量和剥落量分别是0.5714 mg/cm2和0.7143 mg/cm2,仅为无涂层试样氧化增重量和剥落量的1/22倍和1/59倍。Silicide coatings on high-Nb containing TiAl（Nb-TiAl） alloy substrate were successfully prepared by microwave heating pack-siliconizing at 2.6 kW for 2 h.The microstructure,composition distribution and phase constituents of the oxidized and unoxidized coatings were analyzed by means of SEM,EDS and XRD.The SEM observation results show that the outer 15 μm layer of the silicide coatings is almost composed of TiSi2 and NbSi2 with a small quantity of Ti5Si3 and Nb5Si3,and the inner layer is Al-rich layer with thickness about 15 μm.Compared with uncoated Nb-TiAl substrate,the weight gain and spallation of silicide coated Nb-TiAl alloy is much smaller after oxidation experiment at 1000 ℃ for 100 h,which are just 1/22 and 1/59 that of the uncoated sample.Thus the high temperature oxidation resistance of Nb-TiAl alloy can be improved further significantly by microwave heating pack-siliconizing.

关 键 词：高铌钛铝合金 微波加热包埋渗硅法 高温氧化 

分 类 号：TQ343.1[化学工程—化纤工业]