Influence of heat treatment temperature on mechanical behaviour, microstructure evolution and intermetallic formation in DIW processed Al–Cu alloy

A potential approach for fabricating multi-material alloys with complex patterns is direct ink writing (DIW). This study evaluated the effects of heat treatment on the mechanical characteristics, microstructural development, and intermetallic phase formation of aluminium–copper (Al–Cu) alloys fabricated using DIW. The samples underwent isothermal heat treatment at five predetermined temperatures: 500, 550, 600, 650, and 700 °C. The hardness values, which peaked at 816.5 HV at 650 °C, showed significant improvement with variations in temperature. At appropriate heat treatment temperatures, microstructural analysis revealed uniform grains and negligible porosity. The optimum precipitation and intermetallic phase change were responsible for the maximum hardness at 650 °C. The results show that the heat treatment temperature can be tailored to improve the material performance of DIW-fabricated components.