Mechanical Characteristics of Pumimpeller Blades Surface Produced by Electro-Spark Deposition

Abstract

Surface strengthening technology is an important mean to improve the surface or fatigue performance of material. The metallographic structure and microstructure of the coating were analyzed by electrospark deposition test, the hardness, microstructure and abrasion resistance of the pump blade were tested by selecting and controlling the process parameters. The experimental results manifest that EDM can significantly improve the hardness, wear resistance and corrosion resistance of the blade surface, and reduce the consumption of the underwater environment. In addition, in the case of the same electrical parameters, the thickness of the strengthened layer in the argon atmosphere is slightly lower than that in the air, and strengthened surface roughness is significantly reduced. Hence, the reason may be two aspects, one is due to the protection of argon atmosphere, eliminating the impact of oxidation, the droplet easier to spread in the substrate surface, the other hand is similar to the principle of welding. Consequently, the electrode material in the form of a transition to the workpiece in the form of transition to the surface. Due to the small droplets, it can get a relatively low enhanced surface roughness, which is to improve the reliability and extend the life of the pump is of great significance.