IMPROVement THE CAVITATION EROSION RESISTANCE OF Al-mg alloys BY TIG SURFACE REMELTING

Abstract

Aluminum-based alloys (Al-Mg, Al-Si-Mg, Al-Zn-Mg, etc.) are intended for the manufacturing of parts subjected to intense stresses by cavitation erosion. This complex phenomenon includes both the hydrodynamic factors of the liquid and the microstructure, hardness and ductility characteristics of the material. The present paper describes a method of increasing cavitation erosion resistance by using the local TIG remelting technique of the AlMg3 alloys surface. The experimental tests were performed according to ASTM G32-2016 standard. The response of the material to each value of the heat input was investigated by measuring the mass loss as a function of the cavitation time and by analysing the damaged surfaces using the optical and scanning electron microscopy. It has been shown that the TIG surface modification treatment increases the resistance to cavitation erosion of the alloy, as a consequence of the higher chemical and microstructural homogeneity and finishing of the granulation.