Trials of Developing a Superplastic Metal Matrix Composite through Mechanical Interlocking of Ultra-thin Stainless Steel Strands and Zn-22Al alloy utilizing Friction Stir Forming
By Hamed Mofidi Tabatabaei (Kokushikan University), Takahiro Ohashi (Kokushikan University), Tadashi Nishihara (Kokushikan University)

Present research proposes a new method of joining Ultra-thin stainless steel strands (diameter of 12µm×100) and Zn-22Al superplastic alloy through friction stir forming (FSF). a guide slit is cut into a Zn-22Al plate and strands are put into the guide slit. Another plate is placed on top, then the FSF is applied to the upper sheet. As the FSF tool moves, friction stirring occurs and the work-piece flows into the guide slit as a result of plastic flow. This leads to mechanically interlocking the strands in the middle along with bonding Zn-22Al sheets.
The potential of forming a locally fiber reinforced superplastic composite and the possibility of improving mechanical properties of Zn-22Al was investigated experimentally. Influence of FSF process parameter on the state of interlocking was investigated, and mechanical joints between strands and superplastic alloy are evaluated by microstructure observation, tensile and hardness tests along with EDS analysis.