Preliminary geometrical and microstructural characterization of WC-reinforced NiCrBSi matrix composites fabricated by plasma transferred arc additive manufacturing through Taguchi-based experimentation

Abstract

Metal matrix composites enhance the wear and corrosion properties of components in heavy-duty industries. This work reports the preliminary effects of process parameters such as current, linear speed, powder flow rate, nozzle angle, powder gas, shield gas, and center gas at the macro-scale and micro-scale of single-track multiple-layer depositions. The use of plasma transferred arc as an additive manufacturing system yields enough energy for a fast solidification rate of the matrix without compromising the carbide in the composite. The results show that the bead height is mainly affected by the powder flow rate, the powder gas, and the travel speed at the macro-scale. The bead width has a close relationship with powder flow rate, powder gas, and current, the latter contributing to the formation of a slumping phenomenon due to heat accumulation. The volumetric deposition is affected by similar parameters to the bead height. At the micro-scale, the process parameters did not show significant carbide changes but demonstrate its homogeneous distribution. The electron microscope observation exhibited the composite’s high quality due to the fast solidification of the process. The results demonstrate that the porosity is mainly affected by the powder flow rate. By understanding the preliminary contribution of process parameters, this manufacturing process can print near net-shaped parts minimizing the post-processing of metal additive manufacturing components. Therefore, this work contributes to implementing a preliminary experimental methodology to understand the deposition process of WC-reinforced composites in plasma transferred arc additive manufacturing.