Microstructures and wear-corrosion performance of vacuum plasma sprayed and cold gas dynamic sprayed Muntz alloy coatings

As one of the important Cu alloys, brass has been implanted in many fields of architecture or fabrication industry. Muntz (Cu6OZn40) brass alloy was used to manufacture the brass coatings in this study due to showing the best corrosion resistance. Two different spray methods i.e. vacuum plasma spray (VPS) and cold gas dynamic spray (CGDS), were chosen to perform the synthesis of brass coatings aiming to avoid oxidation. Upon utilization of VPS and CGDS techniques, spray process is crucial to the microstructures, phase transformation, mechanical property, and wear and corrosion properties of Muntz alloy coatings. Here results show that no oxidation was characterized in both two processes. Nevertheless, a vaporization of 19.32 wt% Zn occurred during VPS, which would lead to the significant differences in grain size, misorientation distribution, texture and phase composition of VPSed coating from those of CGDSed coating. The CGDSed coating exhibited excellent performances due to a preservation of chemical composition of original feedstock. For example, it yielded a hardness value of 211.8 +/- 9.8 HV0.3, which was nearly two times higher than that of VPSed coating (119.3 +/- 11.6 HV0.3). It was also shown that a significant wear rate reduction ((1.3 +/- 0.018) x 10(-5) v.s. (2.36 +/- 0.39) x 10(-4) mm(3)/mN) and a corrosion resistance enhancement.