Production of (W, Ti)C reinforced Ni-Ti matrix composites

摘要

Production of (Ti, W)C in Ni-Ti matrix by combustion synthesis method was investigated. Samples with various W/Ti ratio and Ni content was produced. Experimental results show that Ni-Ti,(Ti, W)C can be produced by this method. Solution of W in TiC was approved by X-ray diffraction (XRD) and SEM-EDS techniques. Increasing W/Ti ratio in the starting materials increases W-exchange in the carbide phase. Depending on the Ni and Ti content, a critical W/Ti ratio exists above which the carbide phases were found to be WC + (Ti, W)C, and below this critical value the carbide phase is (Ti, W)C. The critical W/Ti ratio decreases with increasing Ni content. Calculating the density of (Ti, W)C with different W/Ti ratio shows that the density of tungsten saturated carbide is close to that of Ti. This is a favorable property when this composite is used as a master alloy for addition to molten titanium in order to produce (W, Ti)C reinforced titanium matrix composites.