Abstract:The high temperature oxidation resistance of RE-Ni-W-B-B₄C-MoS₂ composite coating, the effects of electrodeposition conditions on the morphologies of the coating and the effect of heat treatment temperature on its hardness, abrasion resistance and phase structure were investigated by using scanning electron microscope(SEM), X-ray diffractometer, microhardness tester and abrasion machine. The results show that the oxidation degree of RE-Ni-W-B-B₄C-MoS₂ composite coating is small when the temperature is lower than 700℃, but it increases sharply when the temperature is higher than 700℃. The hardness of RE-Ni-W-B-B₄C-MoS₂ composite coating increases with increasing heat treatment temperature, it comes up to the maximum value at 400℃, but it decreases gradually if the temperature rises continuously. The most favourable abrasion resistance was attained after RE-Ni-W-B-B₄C-MoS₂ composite coating being heat treated at 400℃. Without heat treating, it is mainly amorphous and partially crystallized, but wholly crystallized after being heat treated at 500℃. RE in the composite coating is in the form of CeO₂ and additions of CeO₂ and B₄C can enhance the thermostability of RE-Ni-W-B-B₄C-MoS₂ composite coating.

Key words: electrodeposition; RE-Ni-W-B-B₄C-MoS₂ composite coating; characteristics