Abstract: Low pressure cast ZL114A aluminum alloy was used as the test material. Microstructure and mechanical properties of as-cast ZL114A aluminum alloy as well as the effect of solution treatment on microstructure and properties were studied by means of Jmatpro simulation, Brinell hardness tester, universal testing machine, optical microscope. The results show that the hardness of the as-cast ZL114A aluminum alloy is only 40.4 HBW, the tensile strength and yield strength are only 126.0 MPa and 66.0 MPa, respectively, and the elongation is 14.7%, moreover, the matrix is equiaxed dendritic structure, which is mainly composed of α-Al phase, primary Si phase, smooth and fine Mg₂Si phase and Al and Si eutectic phase. The tensile strength, yield strength and elongation of the alloy in T6 state with solution treatment of 540 ℃ for 6 h are 345.7 MPa, 300.0 MPa and 7.67%, respectively. As the solution time extends to 14.5 h, the properties and microstructure of the alloy change a little. When the solution temperature is 550 ℃, the mechanical properties and microstructure of the alloy are different insignificantly from those of 540 ℃. However, when the solution temperature is 530 ℃, due to insufficient redissolution of Mg₂Si phase, the effect of solution strengthening and dispersion strengthening are relatively low, resulting in poor mechanical properties of the alloy.

Key words: ZL114A aluminum alloy, solution treatment, low pressure casting, mechanical properties, microstructure