Influence of process and test parameters on the dry sliding wear behaviour of Al-Pb alloys produced by mechanical alloying

In the work presented here, the aluminium alloys with lead ranging from 5 to 25 wt% are produced by mechanical alloying (MA) of Al-Pb powders in argon atmosphere. The authors studied the effect of alloy composition and ball to charge ratio on densification as well as wear behaviour of Al-Pb alloys processed through ball milling and attrition milling routes. Powder X-ray diffractometer, scanning electron microscope, optical microscope and hardness and tensile test data are used to characterise the microstructure and mechanical properties of Al-Pb alloys. The influence of lead content, load and sliding speed on wear characteristics of the alloys is examined in dry sliding against EN-24 steel disc, using a pin-on-disc type of tribometer. Further, the tribological behaviour of the alloys is compared to determine an effective way of improving the microstructure, mechanical and tribological properties of Al-Pb alloys. The study reveals that higher ball to charge ratios will be beneficial from the point of view of densification and MA through attrition milling results in better tribological performance of Al-Pb alloys compared to ball milled alloys.