The Influence of Primary Si on Crack Initiation and Propagation in Heat-Resistant Aluminum Alloys Under Different Loading Conditions

The research work of this article mainly focuses on heat-resistant aluminum alloys. By analyzing their failure modes and locations during service, the weak links of alloy crack initiation and propagation are sought. And from the perspective of micro interface stress calculation, stress concentration, crack initiation and propagation, and persistent creep processes of primary Si phases at different scales were calculated and analyzed. Analyze and evaluate the influence and mechanism of the initial Si scale on room temperature loading and high-temperature creep by combining the relationship between microstructure energy changes and the equivalent stress distribution cloud map. At the same time, this article systematically calculates and analyzes the phase selection and microstructure optimization of eutectic piston alloys, studies the influence of alloy composition on the precipitation process and content of coexisting phases in the alloy, and improves the high-temperature microstructure stability and high-temperature fatigue performance of the alloy. To provide material foundation and technical support for the construction of a new type of Al-Si-Cu cast aluminum alloy with multiple multi-scale microstructures and new material design.