Advances in the Structural Integrity of Cold Sprayed Alloys - A Critical Review of Process Models and Mechanical Properties

Abstract

This article explains the impact of an additive manufacturing technique known as cold spray and its applications in alloy design and manufacturing. The process involves the bombardment or impinging the surface of an alloy with micro-sized powders using low reactive gasses. The temperature of gas and powders are much lower than their melting point resulting in no phase transformation. Adhesion happens as a result of metallic bonding and mechanical interlocking. This method is mostly used for protection and material repair in aerospace and automotive applications, but with increasing exploratory applications across various industries. This method that was developed in mid-1980s and applicable for depositing wide range of pure metals, alloys, and composites onto variety of substrate materials. This article provides an overview of the basic principles and processing parameters of cold spray technologies while highlighting the efficiency of the process. The application of this AM technique on some pure metals, dilute and complex concentrated alloys, and the effect of optimised process parameters are discussed in light of current manufacturing processes and research landscape. This AM technique could be a great substitute for most thermal spray coatings where very high temperatures and its associated phase transformation and microstructural evolutions are inevitable. The implication of the results for future research directions are also highlighted.