Tailoring the microstructure, physical, and mechanical properties of pure copper using various additive manufacturing techniques

Abstract

This study focuses on the utilization of additive manufacturing (AM) for enhancing the production of essential copper-based components, due to their exceptional thermal and electrical conductivity attributes. In this context, an original copper-tellurium cast electrode was completely evaluated and compared with AM pure Cu electrodes, which were produced using laser powder bed fusion (LPBF), LPBF followed by hot isostatic pressing (LPBF-HIP), and binder jetting techniques. The investigation demonstrated that pure copper electrodes produced by LPBF-HIP process showed more homogeneous microstructure with the least porosity (0.14 ± 0.05 %). The uniaxial tensile test results demonstrated that the sample produced via the LPBF-HIP process exhibited superior toughness, with a yield strength of 205 MPa and an ultimate tensile strength of 285 MPa. Furthermore, elongation increased significantly, reaching 54 %. Furthermore, the lowest ultimate tensile strength, measured at 223 MPa, was estimated for the binder jet sample (Markforged), while the lowest elongation, at 34 %, was recorded for the LPBF sample. Although the binder jet samples exhibited a smaller average grain size compared to those produced by LPBF and HIP, it has been determined that porosity plays a more significant role in influencing the mechanical and physical properties of this metal. The physical properties, including thermal conductivity and electrical conductivity, of the samples produced via AM showed that the samples produced using HIP exhibited values closest to the reference cast sample, with measurements of 374 W/m·K and 5.72 × 10 7 S/m, respectively. • Various additive manufacturing techniques were employed to produce pure copper components. • The microstructure, physical and mechanical properties of the samples changed with variations in production techniques. • The influence of microstructure on physical and mechanical properties was assessed. • The effect of HIP treatment on removing the porosities and modifying the as-built LPBF samples was studied. • HIPed pure copper sample exhibited a more uniform microstructure, and better properties compared to the other additively manufactured samples.

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