Influence of Dispersant on Microstructure and Tensile Properties of IMC/Al Composite Prepared by FSP

The Intermetallic compound reinforced aluminum matrix composite was prepared by friction stir processing (FSP) technology. The effect of dispersant SiC and CNTs in the composite on the uniformity of microstructures, reinforced phase contents and size and tensile properties of composite was analyzed by scanning eletron microscope (SEM), energy disperse spectroscopy (EDS), X-ray diffractometer (XRD) and tensile tester. The results show that the Ni powder agglomeration was found in IMC/Al composite prepared by FSP. The shape of aggregate was similar stripe and similar oval. The dispersant addition inhibited the agglomeration of Ni powder and improved the uniformity of compound region of composite. CNTs had a better effect on inhibiting agglomeration than SiC. The dispersant addition promoted the Al-Ni in-situ reaction that produced more reinforced phase of Al₃Ni. The dispersant addition improved the mechanical properties of composite. The maximum tensile strength of composite reached 171 MPa after adding CNTs and increased by 15.5% compared with that of composite without dispersant.