Microstructure and Grain Refining Performance of a New Al-Ti-C Master Alloy

Abstract

Control of microstructure features that affect the Al-TiC master alloys grain refining efficiency is leading to improve the aluminum grain refinement. This study has been done to find the solute effect theory to produce new Al-TiC master alloys to get more possibility to control these features. The produced master alloys were examined by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD); also, the influence of them on pure aluminum was studied. Produced Al-6Ti-1C master alloy contained Ti and TiC particles in the aluminum matrix and Al-4Ti-1C contained TiC particles in the aluminum matrix. As the result, the produced Al-6Ti-1C master alloy is a more efficient grain refiner for pure aluminum as compared to the Al-4Ti-1C. This confirms the influence of Ti particles for grain refinement. The results showed that Al-6Ti-1C master alloy had maximum grain refining performance with 2 minutes holding time , at 983 o K temperature , and 1% wt master alloy addition. Finally, a new Al-TiC master alloy with excellent refinement has been prepared successfully.

Effects of Holmium Additions on Microstructure and Properties of A356 Aluminum Alloys

“…By melts modifications with special compounds or elements, the microstructure can be greatly improved. For examples, the TiB 2 , TiC, Al 3 Sc, Al 3 Y, and Al 3 Er compounds serve as heterogeneous nucleation sites to facilitate the nucleation of α-Al crystals [3,6,11,13,30,31]; some active elements adsorbing on the surface of the primary α-Al dendrites advance their flourishing growth due to constitutional supercooling [8,32]. On the other hand, elements such as Sr, P, Na, and RE adsorb on the surface of the eutectic Si phases to inhibit the orientation growths along {200}, {110}, or {101} planes, resulting in short rods or even small granules [13,33,34].…”