Analysis of Friction Stir Welding Behavior of Aluminum Cerium Alloy and Viability for Industrial Application

Abstract

Desire for efficiency and weight reduction in engines has propelled the search for lightweight alloys which retain high mechanical strength at extreme temperatures. A novel aluminum cerium alloy system was developed as a solution; the alloy’s production is inexpensive, and it has exceptional castability and strength at temperatures >300ºC where a typical aluminum alloy would see significant reduction in mechanical properties. There is currently no published research on the friction stir welding (FSW) behavior of cerium-alloyed aluminum. FSW of this material would have numerous applications in the space sector and could also provide a means of repair of costly castings, returning cracked castings to near cast properties. In this thesis, the FSW behavior of an aluminum cerium alloy (Al-10Si-7Ce-4.3Cu-0.4Mg) is examined and resulting weld properties are presented; through implementation of high rotational speeds and slower traverse rates than are used for traditional aluminum FSW, an initial weld profile was formulated and adequate friction stir welds were achieved.