| NiTi intermetallic compound can be potentially used in various applications such as water turbines, propellers and other over-current component due to its excellent corrosion resistance and erosion wear resistance performance. However, processing of NiTi alloys is difficult and the price of NiTi alloys is expensive, so the fabrication of spraying coatings on the surface of metal material is a solution.NiTi coating was deposited on1Cr18Ni9Ti stainless steel substance by arc spraying. Caivation erosion test of the sample was finished by ultrasonic stretching vibration caviation test machine. SEM, X-Ray diffraction and EDS were employed in examing the structure of the NiTi alloy rod and the coating before and after cavitation erosion. The results showed that arc spray coatings deposited with flat particles and remained lamellar structure. The main composition of arc spraying coating were NiTi(B2), TiO and NiO. The oxide content of coating deposited by supersonic arc spraying coating was highest, followed by ordinary arc spraying and by arc spraying in Argon atmosphere was minimum. The micro-hardness of matrix and coatings were tested by micro-hardness equipment. The results showed that the average micro-hardness of fabricated by ordinary arc spraying, supersonic arc spraying and arc spraying in Argon atmosphere were585.OHVo.3,580.1HV0.3,494.8HV0.3respectively. The coating’s hardness increased by27.8%,26.7%and0.8%than that of the matrix. Ni-Ti coating cavitation resistance was tested using ultrasonic vibration cavitation device. It found that cavitation resistance of coatings increased by32.6%,41.4%and60.3%than that of the matrix. The coating deposited by arc spraying in Argon atmosphere has the smallest cavitation erosion weight lost under the same condition. |
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