Tribological properties of Al/diamond composites produced by cold spray additive manufacturing

A range of Al/diamond metal matrix composites using advanced core-shell structured diamond powders was fabricated employing solid-state cold spray additive manufacturing technology. Cold spray technique combined with core-shell structured diamond particles has demonstrated excellent capability to produce dense Al/diamond composites with superior tribological properties. The core-shell structured diamond was easier to deposit than pure Al by cold spray, particularly under low particle impact velocity, implying high potentials as preferential feedstock for cold spray. The wear-resistance performance of the Al/diamond composites produced by nitrogen and helium were investigated. Wear test illustrated that the Al/diamond composites had superior wear-resistance properties comparable to the selective laser meting Inconel 625 and 17 - 4PH alloys. Higher diamond contents in the composites resulted in better wear resistance. Based on the worn track analysis via X-ray computed tomography, the role of the diamond reinforcement in improving the wear-resistance performance was also clarified.