Effect of Alternating Current Frequency on Microstructure and Properties of In-situ Synthesized Al3Ti/Al Composites

Using metal Al as matrix and titanium fiber as reactive source, an Al3Ti/Al composite was fabricated by applying induction heating, and the inductive magnetic field generated by the coil was used to promote the in-situ reaction rate of aluminum and titanium. The reaction temperature was preliminarily judged by differential thermal analysis (DTA) to be about 800℃, and the obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and wear testers. The results show that when the alternating current frequency is 7 kHz, the current is 8 A, and the time is 5 min, the titanium fiber reacts with Al completely, and the dispersed distribution of Al3Ti particles are in-situ obtained, and the average size of the particles reaches 3 μm. Under the condition of 10 N load using air as a medium, the friction coefficient decreases first and then increases with the increase of alternating current frequency. The friction coefficient at the frequency of 7 kHz is the lowest value of 0.2, the wear amount is the least, and the wear resistance is optimal. © 2020, Science Press. All right reserved.