Microstructural and tribological properties of nanostructured Al6061-CNT produced by mechanical milling and extrusion

Abstract

Wear properties of Al6061-CNT nanocomposites have been studied using dry sliding method. Nanostructured Al6061 powder has been prepared using 30 h mechanical milling of atomized powder, and mixed with different percent of CNT. The yielded mixture was subjected to mechanical milling for 0.5 and 4 h. Mixtures were cold compacted, homogenized and extruded to achieve 13 mm diameter round cross section bars. Relative density and hardness of specimens were determined for extruded samples. Maximum relative density was achieved for specimen without CNT which was about 99.848%, while maximum hardness of 236.1 HV was for specimen with 1.25 wt% CNT. Pin on disk method wear test results indicated that weight loss and wear mechanism strongly depends on normal load. At lower normal load, minimum weight loss achieved for Al6061-1.25 wt% CNT nanocomposite at abrasive and delamination mechanisms, while by increasing of normal load, minimum weight loss achieved for specimen without CNT that its wear mechanism was adhesive and delamination.