On the age hardening behavior of thixoformed A356–5TiB2 in-situ composite

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 636; pp. 254 - 262
• Main Authors: Deepak Kumar, S., Mandal, A., Chakraborty, M.
• Format: Journal Article
• Language: English
• Published: 01-06-2015
• Subjects: Age hardening; Dislocation density; Hardness; Microstructure; Particulate composites; Slopes; Tensile strength; Thixoforming
• ISSN: 0921-5093
• DOI: 10.1016/j.msea.2015.03.076

The present article investigates the age hardening behavior of thixoformed A356-5TiB2 in-situ composite prepared by a salt-metal reaction. The non-dendritic feedstock for thixoforming was prepared by a cooling slope casting technique. The results show that the thixoformed A356-5TiB2 composite attains the peak hardness in only four hours. The detailed microstructural analysis of thixoformed composite shows that enhanced ageing can be attributed to high dislocation density generated in alpha -Al matrix due to thermal mismatch and the thixoforming process itself. Furthermore, it was found that thixoforming not only increases the tensile strength of thixoformed composite in peak-aged condition but also increases the ductility by ~7.4%.