Tribological properties of Al-Si-Cu-Mg alloy-based composite-dispersing diamond nanocluster

This paper describes the tribological properties of diamond nanocluster-dispersed Al-Si-Cu-Mg composite with a comparison to those of diamond-like carbon (DLC)-coated Al-Si-Cu-Mg alloy. Al-Si-Cu-Mg composites containing diamond nanoclusters are fabricated in a powder metallurgy process combined with high-energy ball milling and dynamic consolidation. Friction measurements are made at various loads (0.02-0.2 N) and sliding speeds (0.05-5.0 mm/s) to examine the friction coefficient and wear width, compared to those of Al-Si-Cu-Mg alloy and a DLC-coated alloy. The results indicate that the friction coefficient and wear width of the composite have a tendency to reduce with a decrease in the load and sliding speed, and that they show lower values than DLC-coated samples at <0.1 N, and <0.5 mm/s. The topographical and frictional images in the composite are investigated with AFM, and the reduction of friction in the mesoscopic level can be observed in the diamond nanocluster-dispersed composite. (C) 2002 Elsevier Science B.V. All rights reserved.