Abstract: Applications of structure heredity of returns of ZL205A alloy on grain refinement and improving mechanical properties were investigated. The results show that the addition of returns is contributed to refining the grains of alloy, and with increasing returns content, the mechanical properties increase first, and then decrease. The maximum as-cast performance is achieved when returns content is 20%(mass fraction), which is shown by the following indications: the average particle size is measured to be 33 μm, and the tensile strength is improved by 11.6% compared with primary alloy, and the yield strength and elongation are also comparatively higher, 87.6 MPa and 7.5%, respectively. But with further increasing the returns content, the microstructure coarsened and the mechanical properties deteriorate.

Key words: ZL205A alloy; returns; microstructure; properties