Microstructure, hardness, thermal and wear behaviours in Al-10Ni/TiO2 composites fabricated by mechanical alloying

In this study, the effects of milling time and sintering temperature on the microstructural evolutions and thermal properties of Al-10Ni/TiO2 composites fabricated by mechanical alloying were investigated. X-ray diffraction revealed that Al3Ni2 intermetallic phase appeared after 20 h of milling. Also, X-ray diffraction and scanning electron microscopy results revealed that as the milling time increased, a more homogeneous structure and particle size reduction occurred. The differential thermal analysis results showed a series of endothermic and exothermic peaks indicating phase transformation and crystallization during continuous heating. After the sintering, polishing and etching of the pressed composite samples, the surface analysis was examined with an optical microscope and the microhardness was also measured. It was observed that as the sintering temperature increased, the formation of Al3Ni and Al3Ni2 intermetallic phases and the microhardness increased. The maximum microhardness value of the pressed composites was found as 541 +/- 20 HV1 in the Al-10Ni/TiO2 composite sample produced with 20 h milling and sintered at 500 degrees C. In addition, the wear behaviour of the composites was investigated using pin-on-disk wear test under a certain load (5-15 N). It was determined that the mass loss decreased significantly as the grinding time and sintering temperature increased.

Automated summary

This study investigates the effects of milling time and sintering temperature on the microstructural evolutions and thermal properties of Al-10Ni/TiO2 composites fabricated by mechanical alloying. The results show that increasing milling time leads to a more homogeneous structure and particle size reduction, while increasing sintering temperature results in the formation of intermetallic phases and increased microhardness. The wear behavior of the composites also improves with longer milling time and higher sintering temperature, leading to significantly reduced mass loss.