Novel application of ultrasonic cavitation for fabrication of TiN/Al composites

A developed approach for a convenient fabrication of titanium nitride (TiN) particulate reinforced commercially pure aluminum (CP Al) composites via ultrasonic cavitation was proposed. The process involved the addition of large size TiN particles (average particle size of 264 μm) into Al melt at 1033 K. In the meantime, ultrasonic vibration was applied into the melt to comminute the large size TiN particles and disperse the produced fine TiN particles simultaneously. Microstructural characterization indicated that the produced TiN particles were much smaller than the starting TiN particles (average particle size of 15 versus 264 μm) and distributed uniformly in the matrix. The fine TiN particles were stable during the process and had a clean interface with the Al matrix. The ultimate tensile strength increased by up to 45% after the formation of fine TiN particles in the commercially pure Al matrix, whilst the hardness increased by a factor of 3. Dry sliding friction test showed that the coefficient of friction of the composites was more stable and lower than the CP Al matrix.