Article ID Journal Published Year Pages File Type
7974536 Materials Science and Engineering: A 2018 27 Pages PDF
Abstract
This research proposed an in situ casting method for preparing Al3Tip/A356 composites with high strength and good ductility by adding Ti powders into molten A356 at 800 °C. A sampling experiment was firstly carried out to explore the evolution process of Ti powders in the A356 melt. Based on which in situ Al3Tip/A356 composites with 1.5 and 3.0 wt% Ti additions were fabricated respectively. Both the microstructures and tensile properties of samples after T6 heat treatment were investigated. The results showed that blocky Si-substituted Al3Ti particulates were synthesized in the in situ reaction and the formation of which followed a reaction-peeling model. The utilization ratio of Ti powders in the fabricating process could research 70%. In situ Al3Ti particulates existed inside the α-Al crystals of A356 alloy, with the size smaller than 10 µm. Both the equiaxed transition from long columnar dendrite structure and refining of α-Al crystals occurred due to the nucleating effect of Al3Ti. Compared with T6-A356, the yield strength, ultimate tensile strength, and percent elongation of the T6-A356/3.0Ti were improved by 29.2%, 36.0% and 143.6%, respectively. The mechanisms of the improved tensile properties, including the strength and ductility, of the composites were also discussed in this research.
Related Topics
Physical Sciences and Engineering Materials Science Materials Science (General)
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