A parametric study on laser cladding of Ti-6Al-4V wire and WC/W2C powder

Abstract

In this paper, laser cladding of Ti-6Al-4V wire and WC/W2C powder to produce metal matrix composite clads with a high ceramic reinforcement and a wider clad width was investigated. Taguchi design of experiments and multiple regression models were used to support this. Single clad deposition of Ti-6Al-4V wire and WC/W2C powder was made on a Ti-6Al-4V substrate using wire and powder co-feeding systems. Clad samples were made at varying processing parameters using L9 orthogonal experimental matrix data. The clad geometries (height and width) and the weight, obtained using a Talysurf CLI 1000 surface profiler and a weighing scale with a sensitivity of 0.0001 g, were presented and analysed. The results showed that a process condition of 1800 W laser power, 300 mm/min traverse speed, 700 mm/min wire feed rate and 30 g/min powder feed rate produced the composite clads with the highest reinforcement fraction of 76 ± 1 wt%, clad height of 1.57 ± 0.03 mm and clad width of 3.91 ± 0.05 mm. This process condition resulted in a clad with the highest signal to noise ratio of 37.67 for the WC/W2C reinforcement and the geometrical aspect ratio (H/W) of 0.40 which lies within the range of 0.42 ≥ (H/W) ≥ 0.13 to prevent the formation of inter-run porosity in deposited overlap clads. The multiple regression model obtained was able to predict the values of the output characteristics with an accuracy of 92 %. The method employed in this study could be easily implemented when other different materials are investigated to result in the optimisation of the process with fewer experimental runs.