Effect of network size on mechanical properties and wear resistance of titanium/nanodiamonds nanocomposites with network architecture

The Ti/nanodiamonds (NDs) composites with various network size were fabricated by spark plasma sintering (SPS) technique. The microstructure, mechanical properties and wear resistance of the nanocomposites were investigated. Experimental results showed that all the Ti/NDs nanocomposites exhibited pure a-Ti with in-situ formed nano-TiC and residual NDs phases. Hardness and compressive yield strength for the nanocomposites showed great enhancement compared to that of pure Ti while without much variation among different network size. Higher tensile yield strength and acceptable ductility were achieved for the composites; however, the ductility presented an increasing trend (from 8% to 33%) with decrease of the network size. The friction coefficient and wear weight loss of the nanocomposite were lower than that of the pure Ti and the wear resistance was improved with decreasing network size. The excellent integrated properties for the Ti/NDs nanocomposites with smaller network size (matrix particle size of 15--53 mu m) are resulted from a combination of quasi-continuous network microstructure, TiC and residual ND reinforcements strengthening and network interface strengthening.