Effects of Heating Temperature and Holding Time on Microstructure and Mechanical Properties of Thixoforged A356 Aluminum Alloy Parts
- Resource Type
- Original Paper
- Authors
- Liu, Yingze; Jiang, Jufu; Xiao, Guanfei; Zhang, Ying; Huang, Minjie; Wang, Ying; Zhu, Liang
- Source
- Journal of Materials Engineering and Performance. 32(5):2062-2073
- Subject
- A356
mechanical properties
TEM
thixoforging
- Language
- English
- ISSN
- 1059-9495
1544-1024
In order to obtain the optimal parameters for thixoforging of A356 aluminum alloy parts, the effects of heating temperature and holding time on the microstructure and mechanical properties of the formed parts with or without T6 heat treatment obtained via thixoforging hot-deformation A356 aluminum alloy directly heated to semi-solid temperature were investigated. Microstructure results showed that lower temperature and shorter holding time refined the grains. The tensile tests results showed that optimal parameters for thixoforging of A356 were heating temperature of 590 °C and holding time of 1 min. TEM results showed that needle-like β" aging precipitated particles with a size of 5 × 5 × 50 nm and equiaxed silicon particles of 50 nm were uniformly distributed in the matrix after T6 heat treatment, which were the strengthening phases of A356 alloy. The needle-like β’’ phases were parallel to the < 001 > crystal orientation of the matrix. The strengthening phase precipitated by aging increased the yield strength and tensile strength and decreased the elongation. The thixoforging parts under optimal parameters exhibited a yield strength of 291.3 MPa, the tensile strength of 324.9 MPa and the elongation of 10.2% after standard T6 heat treatment.