Fabrication and tribo characteristics of in-situ polymer-derived nano-ceramic composites of Al-Mg-Si alloy

Polymer-derived nano ceramic metal matrix composites (PDC-MMC) have potential as wear-resistant materials. PDC-MMC are obtained from preceramic polymers after pyrolysis. To develop in-situ PDC-MMC, ball-milled Polymethylhydrosiloxane polymer particles were dispersed in an industrial-grade Al-Mg-Si matrix by Friction Stir Processing (FSP). Tribological properties were evaluated at variable loads using a reciprocating ball-on-flat method. PDC-MMC showed 67.2% reduction in wear volume loss. Improved resistance to abrasion and delamination could be reasoned for excellent wear resistance. Under the severe plastic deformation during FSP, the uniform ceramic distribution resulted in compact bonding with the metal matrix and yielded better wear properties. The dominant wear mechanism of PDC-MMC changed from abrasive to adhesive.