Grain Refinement of Al-5Ti-0.62C-0.2Nd Grain Refiner for Commercial Pure Aluminum and Its Effect on Mechanical Properties

Abstract

It is well known that the mechanical properties of commercial pure Al are influenced by size of α-Al dendrites. In the present work, Al-5Ti-0.62C-0.2Nd grain refiner was prepared by a pure molten aluminum thermal explosion reaction, and its effect on grain refinement and mechanical properties of commercial pure Al was investigated. Microstructure and phase composition show that Al-5Ti-0.62C-0.2Nd grain refiner consists of α-Al, granular TiC, lump-like TiAl 3 , and block-like Ti 2 Al 20 Nd. Grain-refining tests on commercial pure Al show that an Al-5Ti-0.62C-0.2Nd grain refiner has better refining performance compared with Al-5Ti-0.62C grain refiner. With addition of 0.2-wt.%-Al-5Ti-0.62C-0.2Nd grain refiner, the average grain size of commercial pure Al can be refined from roughly 2800 to 155±5 µm effectively, and it has higher resistance to grain-refinement fading. On account of the grain refinement, the tensile strength and elongation are increased by approximately 18.3% and 83.5%, respectively.