Tribotechnical Properties of Sintered Antifriction Aluminum-Based Composite under Dry Friction against Steel

The disadvantage of antifriction Al-Sn alloys with high tin content is their low bearing capacity. To improve this property, the aluminum matrix of the alloys was alloyed with zinc. The powder of Al-10Zn alloy was blended with the powder of pure tin in the proportion of 40/60 (wt.%). The resulting mixture of the powders was compacted in briquettes and sintered in a vacuum furnace. The sintered briquettes were subjected to subsequent pressing in the closed press mold at an elevated temperature. After this processing, the yield strength of the sintered (Al-10Zn)-40Sn composite was 1.6 times higher than that of the two-phase Al-40Sn one. The tribological tests of the composites were carried out according to the pin-on-disk scheme without lubrication at pressures of 1-5 MPa. It was established that the (Al-10Zn)-40Sn composite has higher wear resistance compared with the Al-40Sn one. However, this advantage becomes insignificant with an increase in the pressure. It was found that the main wear mechanism of the investigated composites under the dry friction process is a delamination of their highly deformed matrix grains.