Laser powder bed fusion additive manufacturing of highly conductive parts made of optically absorptive carburized CuCr1 powder

• Published in: Materials & design 2021-01, Vol.198, p.109369, Article 109369
• Main Authors: Jadhav, Suraj Dinkar, Dhekne, Pushkar Prakash, Brodu, Etienne, Van Hooreweder, Brecht, Dadbakhsh, Sasan, Kruth, Jean-Pierre, Van Humbeeck, Jan, Vanmeensel, Kim
• Format: Article
• Language: English
• Subjects: Additive manufacturing; Carburized CuCr1 powder; Copper reflectivity; Laser powder bed fusion; Metal matrix composite; Selective laser melting
• ISSN: 0264-1275; 1873-4197; 1873-4197
• DOI: 10.1016/j.matdes.2020.109369

Fabrication of fully dense and highly conductive copper alloy parts via laser-based additive manufacturing (L-AM) is challenging due to the high optical reflectivity of copper at λ = 1060 – 1080 nm and high thermal conductivity. To overcome this, the use of optically absorptive surface-modified copper powders is being evaluated in the laser powder bed fusion (LPBF) process. Although the surface-modified powders exhibit high optical absorption at room temperature, not all of them allow the fabrication of fully dense parts at a laser power below 500 W. Accordingly, this article proposes the use of optically absorptive carburized CuCr1 powder for the consistent fabrication of copper parts. Moreover, a densification mechanism of parts is discussed to explain the distinct LPBF processing behavior of different surface-modified powders, such as carburized CuCr1 and carbon mixed CuCr1 powders, albeit having similar room temperature optical absorption. This investigation clearly outlines the advantage of a firmly bonded modified layer present on the surface of the carburized CuCr1 powder over a loosely attached carbon nanoparticle layer present in the carbon-mixed CuCr1 powder. Apart from the successful fabrication of CuCr1 parts, fabricated parts are subjected to two different post-heat treatments, and it is shown that the final properties can be customized by applying tailored post-heat treatments. [Display omitted] •Production of optically absorptive carburized CuCr1 powder•Carburized CuCr1 powder for reliable laser-based additive manufacturing of highly conductive parts•Laser powder bed fusion processing behavior of surface-modified (carbon-mixed and carburized CuCr1 powders) copper powders•Tailor-made electrical, thermal, and mechanical properties by the application of post-heat treatments•Use of carburized copper alloy powders for the manufacturing of ceramic particle reinforced metal matrix composites