Scandium in Commercial Wrought Aluminum Alloys

This chapter reviews commercial applications for scandium (Sc)-containing wrought aluminum (Al) alloys. Advantages from alloying Sc with aluminum Al include (1) refined grain structure in billets, ingots and weldments; (2) increased resistance to recrystallization; (3) strengthening from stable Sc-containing dispersoids and (4) improved nucleation of strengthening phases. These effects are well documented in the literature as highlighted in several detailed reviews. Efforts to commercialize Sc-containing alloys were initiated in the late 1960s in the Former Soviet Union and at Alcoa in the United States. Alcoa was granted a patent in 1972 covering Sc additions in commercial wrought alloys. Subsequently, hundreds of patents were granted for Sc-containing alloys, but commercial applications have been limited due to Sc availability. In view of current and potential future Sc resources, production of Sc-containing alloys conceivably will find widespread commercial applications once a stable supply market is established.