Preparation and characterization of nanodiamond reinforced aluminum matrix composites by hot-press sintering

In the present paper, aluminum matrix composites (AMCs) reinforced by nanodiamond (ND) were fabricated by hot-press sintering. The morphology and microstructure of ND/Al composite powders for different milling hours were observed. The effect of ND content on microstructure, mechanical properties and tribological behavior of AMCs was investigated. The relative density, hardness, compressive strength and wear resistance of AMCs with different ND contents were compared. The flake-shape aluminum particles with uniformly distributed ND particles were formed by ball milling for 15 h. A laminated structure of AMCs was formed by hot-press sintering at 550 degrees C for 5 min. ND was distributed at the grain boundary of Al matrix. At the interface between Al and ND, a layer of Al with high dislocation density was formed, which was closely connected with a layer of amorphous carbon. With increasing of ND content, more and larger pores were presented in AMCs, which caused a decrease in relative density. The hardness, compressive strength and wear resistance of AMCs were significantly improved in comparison with sintered aluminum. The AMC with 2.5% ND obtained the highest hardness and compressive strength and the lowest coefficient of friction and wear rate.

Automated summary

In this study, aluminum matrix composites reinforced by nanodiamond were fabricated by hot-press sintering. The effect of nanodiamond content on the microstructure, mechanical properties, and tribological behavior of the composites was investigated. Increasing nanodiamond content resulted in improved hardness, compressive strength, and wear resistance of the composites.