Microstructure and tribological behavior of SPS processed Fe/Ti-15wt.%Cu-based metal matrix composites with incorporated waste Ti-chips

摘要

In present work, the Fe/Ti-15wt.%Cu-based metal matrix composites with three different Fe/Ti weight percent ratios (i.e., 40/25, 25/40, 5/60) and constant additions of non-metallic additives (i.e., 5 wt.% graphite, 5 wt.% SiC, and 10 wt.% ZrO2) were investigated. An innovative and ecologically friendly approach for laboratory preparation of the experimental composite materials was based on the secondary utilization (recycling) of the waste Ti-chips (turnings) from conventional machining operations. The material mixtures for the fabrication of the studied composites were prepared by common powder metallurgy pre-operations followed by final material processing using spark plasma sintering (SPS). The microstructure of the SPS-fabricated composite materials consisted of sintered grain matrix with various amounts and distribution of Ti-chips. The friction and wear behavior of the composites was analyzed from performed tribological measurements employing "ball-on-disc" test method. The results showed that the coefficient of friction was mostly decreasing with increasing the sliding speed and the amount of Ti-chips in the composites. The lowest abrasion wear rate exhibited the composite with 40 wt.% of Ti-chips thanks to its optimal microstructure with appropriate hardness and beneficial wear mechanisms characteristics.