论文部分内容阅读
利用包埋渗结合化学镀技术在铌合金表面制备了复合涂层,研究了涂层在退火过程中的元素扩散行为及涂层的高温抗氧化性能。结果表明:复合涂层以晶态Ni和Al_3Nb相为主;退火过程中渗层中的Al元素向外扩散,涂层转变为晶态,形成了Ni Al_3、Al_3Nb、Ni Al相。对退火前后的涂层进行1000℃恒温氧化实验,20 h后沉积态涂层的增重为7.7 mg/cm~2,表面主要含Ni O、Al_2O_3、Ni Al相;退火态涂层样品的增重为4.9 mg/cm~2,表面生成了Al_2O_3、NiNb_2O_6、NiAl_2O_4等相。氧化后涂层与基体结合良好。退火态涂层表面由于富Al元素,氧化后形成较多的Al_2O_3,比沉积态的涂层能更有效地减缓氧化进程,提高铌合金的抗氧化性。
The composite coating was prepared on the surface of niobium alloy by embedding combined with electroless plating technology. The element diffusion behavior and the high temperature oxidation resistance of the coating during the annealing process were studied. The results show that the Ni - Al and Al_3Nb phases are the main coatings in the composite coating. Al in the coating diffuses outward during the annealing process, and the coating turns into a crystalline phase, forming NiAl_3, Al_3Nb and NiAl phases. The coatings were annealed at 1000 ℃ before and after annealing. The weight gain of the deposited coatings was 7.7 mg / cm ~ 2 after 20 h. The surface of the coatings was mainly composed of NiO, Al_2O_3 and NiAl phases. Weight 4.9 mg / cm ~ 2, the surface generated Al_2O_3, NiNb_2O_6, NiAl_2O_4 and other phases. Oxidized coating and the substrate well. The surface of the annealed coating is more Al 2 O 3 formed by the oxidation of Al than the as-deposited coating, which can reduce the oxidation process more effectively than the as-deposited coating and improve the oxidation resistance of the niobium alloy.