Mg based nano-composites fabricated by friction stir processing

Friction stir processing (FSP) has been applied to incorporate 5–10 vol.% nano-sized SiO2 into an AZ61Mg alloy matrix to form bulk composites. The nano-particles were uniformly dispersed after four FSP passes, and the average grain sizes of the composites varied within 0.5–2 μm. The composites nearly doubled the hardness of the base material and exhibited high strain rate superplasticity.