Effects of ageing and cryo-ageing treatments on microstructure and hardness properties of AA2014–SiC MMCs

Abstract

Abstract: In this study, microstructure and hardness effects of cryogenic and ageing heat treatments applied to AA2014–SiC composites containing vol. 0.5, 1, 2 and 4% SiC reinforcing ratio have been investigated. SEM, EDS, XRD and MAP analyses have been used in the determination of microstructural properties. Macro hardness measurements have been implemented for the investigation of hardness effects. Through the dissolution and cryogenic processes applied, alloying elements such as Cu, which has a direct effect on the formation of secondary phase in the structure, can be homogeneously dispersed in the microstructure. It has been also found that there is a significant increase in the hardness level due to the applied cryogenic treatment. A significant homogenous distribution of alloys is obtained in the MAP analysis after the cryogenic process. This is the reason why the cryogenic cooling process can be working dynamically, especially in ageing applicable alloys. Graphical Abstract: [Figure not available: see fulltext.] © 2018, The Indian Institute of Metals - IIM.