Improved Grain Refinement Process for Aluminum (Aluminum IOF)
A new method of grain refining aluminum employing the in-situ formation of boride nuclei in molten aluminum has been developed and tested (U.S.P.#5,935,295). This method produces nuclei that are more uniform in size and are simpler to prepare than conventional grain refiners. Replacing conventional master alloy rod refiners provides energy, capital and environmental savings. Grain refining improves many metallurgical properties such as resistance cracking, ductility and surface finishing characteristics. Almost all aluminum cast is grain refined with titanium boride (TiB 2 ) nuclei. Trace amounts of titanium are inherent in molten aluminum. In this new process, boron readily reacts with titanium to form insoluble TiB 2 nucleation sites for the production of fine grains.