THE EFFECT OF HARDENING OBTAINED AFTER TIG REMELTING ON THE RESISTANCE OF THE 7075 ALLOY STRUCTURE TO CAVITATION EROSION

The phenomenon of cavitation is present in all areas of industry where liquids are in motion. The recognition of its effects is given by the destruction of the material structure through erosion, by vibrations and noise, as well as by the modification of the hydrodynamic field leading to a decrease in energy performance (efficiency). Correlated with the current trends in the use of aluminum alloys in various components, such as boat engine propellers and cooling pump rotors of car mills, the problem arises of improving the characteristics that determine their increased resistance to cavitation erosive stresses. In this regard, the paper presents the results of research into the behavior and resistance to erosion by vibratory cavitation of the structure of the 7075 aluminium alloy in the T651 state hardened by TIG remelting. Comparing the results obtained with those obtained on the semi-finished structure and obtained through artificial aging heat treatment regimes, shows a significant increase in the resistance of the structure to the cyclic stresses of the microjets developed by the hydrodynamics of vibrating cavitation.