Crystallographic Texture in the Friction-Stir-Welded Metal Matrix Composite Al6061 with 10 Vol Pct Al2O3

Friction stir welding (FSW) is an important, relatively new joining technology particularly for aluminum alloys and metal matrix composites (MMCs). Metal matrix composites are light weight and have good stiffness and strength-perfect for aerospace and other modern industrial applications. However, MMCs are difficult to join by traditional fusion welding processes due to welding defects and poor joint strength. To better understand the joining process in friction-stir-welded MMCs, investigation of the crystallographic texture of the weld and of the interface between the metal matrix and reinforcing particles is needed. The crystallographic texture and particle-matrix interaction of FSW Al6061-10 vol pct alumina have been studied in this article. Using electron backscatter diffraction (EBSD), the texture gradient of the FSW MMC has been shown to have similar trends to that of an unreinforced Al alloy, but with significantly larger grain size in general. Fracture and redistribution of the reinforcing alumina particles in the weld nugget were also observed.