Thermal analysis of aluminum alloys as a tool to evaluate the grain refiners efficiency

Al-5%Ti-1%B and Al-5%Ti-1C master alloys were used to grain refine some aluminum alloys. The factors that affect the efficiency of grain refiners (addition rate, holding time, pouring temperature and metal composition) were studied. Thermal analysis was used to evaluate the efficiency of the two grain refiners in parallel with a conventional method (KBI test). The characteristic parameters of the cooling curves have been correlated to the grain size of the castings. It was found that thermal analysis could be used as a tool to evaluate the efficiency of the grain refiners of aluminum alloys prior to casting. Also, it was found that Al-5%Ti-1%C master alloy is more efficient grain refiner than Al-5%Ti-1%B.