Coarsening Kinetics of Semi-solid A356–5wt%TiB2 in situ Composite

• Published in: Transactions of the Indian Institute of Metals Vol. 68; no. 6; pp. 1075 - 1080
• Main Authors: Deepak Kumar, S., Acharya, Mihira, Mandal, A., Chakraborty, M.
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 01-12-2015
• Subjects: Chemistry and Materials Science; Corrosion and Coatings; Materials Science; Metallic Materials; Technical Paper; Tribology; Ostwald ripening; TiB; Cooling slope casting; A356 alloy; Coarsening
• ISSN: 0972-2815; 0975-1645
• DOI: 10.1007/s12666-015-0648-z

An attempt has been made to investigate the coarsening behaviour of semisolid A356–5wt%TiB
2
in situ composite produced by Cooling slope casting. It was found that the average grain size of α-Al in the gravity-cast alloy got reduced from 98 to 48 µm in the semi-solid A356–5TiB
2
composite. The primary α-Al in the composite were found to undergo substantial spheroidisation after 5 min at a reheating temperature of 585 °C (
f
s
 = 0.5). Further, increase in holding time from 5 to 15 min resulted in grain growth of α-Al in both the alloy and the composites. The coarsening rate constant, K, for A356–5wt%TiB
2
composite was found to be 339.73 μm
3
/s which is 32 % lower than that of semi-solid A356 alloy, thus proving the effectiveness of TiB
2
particles towards grain coarsening.