چكيده به لاتين
Abstract:
Mechanical properties of Al-Si-Cu alloys can be improved by precipitation hardening. Adding magnesium to this alloy not only improves its hardness and strength, but also has a significant impact on the aging rate.
In this study, the effect of semi-solid forming (SIMA process) of Al-10.5Si-3Cu-0.2Mg alloy on the microstructure and mechanical properties is investigated. Plastic deformation and recrystallization were implemented on the samples to fulfil the desired microstructure. To achieve this, specimens were cold worked to 10, 15, and 20% plastic deformation, followed by reheating process at 569°C for 10, 15, 20, 25, and 30 minutes. After microstructural evaluation, optimum reheating time for each deformation was identified. Finally, samples were pressed under a fixed load to the desired shapes. By comparing microstructure characteristics and mechanical properties of all samples, those which were produced by thixoforming method showed better tensile strength, yield strength and relative elongation than as-cast samples.
Ultimate tensile strength of 412 MPa, yield strength of 300 MPa, and elongation of 4.54 % was achieved by Precipitation hardening of thixoformed samples.
Keywords: Al-Si-Cu-Mg Alloys, Thixoforming, Age Hardening, Mechanical Properties
