Abstract
Aluminum alloy B319 (Al-Si-Cu) is commonly used in automotive powertrain component applications, primarily due to its low density and excellent castability. However, in the as-cast state, B319 Al alloy often exhibits inferior mechanical properties due to the presence of coarse secondary phases, and elongated, large needle-like Si particles. Heat treatment plays a critical role in modifying these microstructural features, particularly through the refinement or spheroidization of Si particles and the dissolution of Al2Cu, which collectively influence mechanical behavior and electrical conductivity. In the present work, B319 Al alloy was fabricated through gravity casting using a permanent cast-iron mold. The study investigates the effects of solutionizing duration, and natural aging time on the alloy’s microstructure, focusing on the evolution of Si morphology and the dissolution of Al2Cu. The relationship between microstructural evolution under heat treatments and the alloy’s hardness and electrical conductivity was further explored.