Kinetic behaviour of TiB2 particles in Al melt and their effect on grain refinement of aluminium alloys
(1. Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
2. School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China)
2. School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China)
Abstract: Solidification experiments were carried out to investigate the kinetic behaviour of TiB2 particles in Al melt and their effect on the grain refinement of commercially-pure Al. A model was proposed to describe the kinetic behaviour of TiB2 particles during the whole process from the addition of TiB2 to the melt to the freezing of the melt. The results indicate that TiB2 particles are not stable in Al melt. They may dissolve and coarsen during the holding period and grow during the cooling period of the melt. The kinetic behaviour of TiB2 particles in the melt has a great influence on their number density and the grain refinement. Solute Ti addition can suppress the dissolution, Ostwald ripening and growth behaviours of TiB2 particles.
Key words: TiB2 particles; kinetic behaviour; grain refinement; aluminium alloy