Wear behavior of spark plasma sintered Al2124 aluminum alloy containing carbon nanotubes

In this work, the wear behavior of spark plasma sintered Al2124 alloy and its composite containing 1 wt.% carbon nanotubes (CNTs) was investigated at a constant sliding speed and different loads against AISI 4140 steel counterface using pin-on-disk configuration. It was found that the addition of CNTs improved wear resistance of Al2124 alloy under lower loads. At higher loads, remaining pores caused crack development and propagation and consequently severe delamination resulting in poor wear resistance of the composite as compared to the monolithic alloy. Mixed modes of wear were observed for the monolithic alloy and the composite. Under lower loads, the composite mainly displayed abrasion with some localized delamination whereas the monolithic alloy showed significant delamination. Under intermediate loads, adhesion was found to be dominant for the composite as compared to microploughing observed for the monolithic alloy. Under the highest applied load of 25 N, the composite displayed severe subsurface fracturing and delamination in the form of large flakes as compared to the monolithic alloy in which the delamination was less intense due to the formation of a stable oxide layer.