Process Parameters Impact on Deposition Quality and Heat Conduction through Novel Cold-Sprayed GrCop42 on Inconel718

In recent years, the capability of cold spray (CS) technology has evolved from a coating technique to an advanced additive manufacturing method, driven by inherent process advantages over traditional thermal spray techniques [1]. CS enables the production of thick, dense deposits of metallic feedstock, and high-quality interfaces between dissimilar metals in traditionally unachievable geometries, such as inner diameters < 70mm [2].

Compared to traditional thermal spray processes, CS ofers distinct advantages, including the absence of a heat-afected zone, retention of feedstock properties, enhanced sustainability and reduced lead times, as well as alignment with circular economy principles[3]. CS is widely viewed as an enabler of industry 4.0 [4], [5].

CS deposition of GrCop42 (Cu alloy) onto Inconel 718 (Ni alloy) was investigated. With Cu's high thermal conductivity and Ni's retention of strength and creep resistance at extreme temperatures, Cu-Ni CS bi-metallics ofer a potential route for manufacture high-integrity components capable of managing large cooling loads. Such functionally graded multi-materials are active research and development interests for application in aerospace (e.g., regenerative rocket cooling and multi-material nozzles) and energy (e.g., tokamak cooling) industries [6], [7].

Given the novelty of CS deposition of Cu onto Ni, various process parameters were trialled, targeting maximum deposition eficiency. Subsequent characterisation examined particle-substrate interactions and included microstructure analysis, composition, adhesion and cohesion strength, and the mechanical and physical properties of each deposit. Substrate behaviour during deposition was also analysed. Thermal flows through the substrate, across the interface, and within the deposit were quantified, demonstrating the influence of deposition (and interface) quality on thermal dissipation and therefore suitability for cooling applications.

This work highlights how process optimisation advances CS as a sustainable, low- carbon method for creating high-integrity components to meet demanding thermal management challenges.