GH4169高温合金上等离子喷涂NiAl涂层的去除

Removal of plasma sprayed NiAl coating from GH4169 superalloy substrate

研究了去除GH4169镍基高温合金基体上等离子喷涂NiAl涂层的方法,探讨了机械去除法、电化学去除法和化学去除法的可行性,发现只有化学去除法可行,且最佳工艺参数为:硝酸/水体积比1∶1,醋酸(添加剂)5g/L,温度25℃。该法不仅可以较好地去除涂层,对基体不造成腐蚀,且不影响再喷涂涂层的结合强度和力学性能。

The removal of plasma sprayed NiAl coating on GH4169 Ni-based superalloy substrate was studied.The feasibility of mechanical,chemical,and electrochemical methods was discussed.Only the chemical removing method was found to be feasible.The optimal operation parameters were determined as follows:volume ratio of nitric acid to water 1:1,acetic acid as an additive 5 g/L,and temperature 25°C.This method can remove the coating efficiently without corrosion of the substrate and influence on the bonding strength and mechanical properties of the coating resprayed.