Effect of Alloying Elements on the Erosion–Corrosion Behaviour of Cu-Based Alloys

Abstract

This study used a powder metallurgy (P/M) to prepare a sample of a Cu / 9.5 % Al alloy and add alloying elements (9.5 % Al five % Ni 0.9 % Mn 4.5 % Fe 0.2 % Ge) to it. The Cu / five % Ni alloy has been used for comparison with other research alloys. The powders were mixed for six hours and pressed under 750 MPa. The samples were sintered at 550 °C for two hours, and then the temperature was raised to 950 °C for a period of 180 min with a heating rate of ten °C / min under an inert gas environment with a continuous stream of argon. It was then left to cool inside the furnace. After this, several heat treatments were used. Some tests were carried out, such the scanning electron microscopy (SEM), energy dispersion spectrometer (EDS), X-ray diffraction (XRD), Vickers micro-hardness and the erosion–corrosion test. The alloy Cu / five % Ni showed the least hardness. The addition of Ni, Mn and Fe to the Cu / 9.5 % Al alloy increased the hardness, and these additions caused a relative increase in the resistance to erosion–corrosion. However, it also caused a large increase in the resistance to erosion–corrosion when adding Ge to the alloy Cu / 9.5 % Al / five % Ni 0.9 % Mn 4.5 % Fe 0.2 % Ge when immersed in seawater. Additionally, it demonstrates a high hardness. These improvements were attributed to an enhancement of the properties of alloy-based Cu – 9.5 % Al, which is used in the marine industry.