Friction stir welding (FSW) has been generating interest in association with friction stir processing (FSP), a new technique that employs FSW tooling. FSP is being investigated as a thermo-mechanical processing tool to transform a heterogeneous microstructure into a more homogenous microstructure.However, very little data is available on the use of FSW for processing composite materials. In this study, a novel method of local manufacture of metal matrix composites (MMCs) using FSW is proposed and its application to friction stir spot welding (FSSW) is described. Trials investigating local manufacture of aluminum oxide particulate reinforced 6063 Al by friction stirring were carried out on a modified milling machine. The results are discussed in terms of weldability and residual microstructure.