Friction and wear behaviour of cast Al 6063 based in situ metal matrix composites

Al 6063 based in situ composites were manufactured from Al-10%Ti and Al-3%B master alloys by liquid metallurgy route. The in situ TiB(2) reinforced Al 6063 composites were synthesized through the exothermic reaction between Al-10%Ti and Al-3%B master alloys, which were used in the ratio of 1:2 respectively in Al 6063 matrix alloy. Tribological properties of both Al 6063 matrix alloy and the developed in situ composites have been evaluated. Dry sliding friction and wear tests were carried out using a pin on disc type machine with steel counter disc hardened to HRC60. A load range of 10-50 N with the sliding velocity varying from 0.209 m/s to 1.256 m/s were adopted. Results have revealed that the developed in situ composites have lowered coefficient of friction and wear rates when compared with Al 6063 matrix alloy under all the test conditions studied. The excellent wear resistance of the in situ composites results from the formation of fine TiB(2) particles uniformly dispersed within the Al 6063 matrix alloy. The coefficient of friction of both matrix alloy and in situ composites decreased with increase in load, whereas it increased with increase in sliding velocity. However, wear rates of both matrix alloy and in situ composites increased with increase in both load and sliding velocity. (C) 2011 Elsevier B.V. All rights reserved.