A developed method for producing in situ TiC/Al composites by using quick preheating treatment and ultrasonic vibration

Quick preheating treatment of Al-Ti-C was introduced in the fabrication of in situ TiC/Al metal matrix composites in our research. Al-Ti-C pellets were preheated in the furnace at 750°C, in which the pure aluminum was melted. After adding the preheated pellets into the molten aluminum, the thermal explosion reaction of Al-Ti-C took place in a short time. In situ TiC particles synthesized in the pure molten aluminum were spherical in morphology and most of which were smaller than 1 μm in size. The synthesizing temperature of in situ TiC/Al composites was decreased significantly by using the quick preheating treatment, at least 150°C lower than those used in the conventional methods. In addition, high-intensity ultrasonic vibration was applied into the melt to disperse TiC particle-reinforcement into the matrix and degas the melt as well. In situ TiC particles were distributed uniformly in the matrix, and the porosity in the composites was below 1% due to the effect of ultrasonic vibration. Furthermore, the microhardness test indicated that a homogeneous microstructure of in situ TiC/Al composite was obtained.