The Grain Refinement Of 7050 Alloy Using Al-5ti-1b And Al-3ti-0.15c Grain Refiners

The morphologies of particles in commercial Al-3Ti-0.2C and Al-5Ti-1B alloy used in the refining experiments were investigated and the grain refining response to 7050 alloy was studied in this paper. The results show that Al-3Ti-0.2C master alloy failed to produce an adequate grain refinement at an equal addition level to that which sufficed with the Al-5Ti-1B alloy. With increasing the holding time, settlement phenomena of TiC particles and TiB2 particles in 7050 melt were both investigated and the settling time of the particles did not match with the results calculated by Stoke's law. Based on the experimental results, the efficiency of grain refinement for 7050 casting using Al-3Ti-0.2C grain refiners seems weaker than those using Al-5Ti-1B grain refiners.