The performance of Al-Ti-C grain refiners in twin-roll casting of aluminium foilstock

The master alloys based on the Al-Ti-B system have been used extensively for refining the grain structure of aluminum alloys. The quality-related problems linked with the TiB2 particles, however, have generated an interest in the Al-Ti-C grain refiners as an acceptable replacement for Al-Ti-B master alloys. TiC particles are smaller than the TiB2 particles and are less prone to agglomeration. Al-3Ti-0.15C grain refiners have been in use for some time in several alloy systems. Much of the work reported on this alloy, however, has been from DC casting while performance data in strip casting is not available. In the present work, a commercial Al-3Ti-0.15C grain refiner was employed in the twin-roll casting of AA8111 foilstock. Its grain refining efficiency was compared with that of the Al-5Ti-0.2B master alloy, the standard grain refiner in aluminium industry for the manufacture of aluminium foil products.