Open-cellular copper structures fabricated by additive manufacturing using electron beam melting

Cu reticulated mesh and stochastic open cellular foams were fabricated by additive manufacturing using electron beam melting. Fabricated densities ranged from 0.73 g/cm3 to 6.67 g/cm3. The precursor Cu powder contained Cu2O precipitates and the fabricated components contained arrays of Cu2O precipitates and interconnected dislocation microstructures having average spacings of ∼2 μm, which provide hardness values ∼75% above commercial Cu products. Plots of stiffness (Young's modulus) versus density and relative stiffness versus relative density were in very close agreement with the Gibson–Ashby model for open cellular foams. These open cellular structure components exhibit considerable potential for novel, complex, multi-functional electrical and thermal management systems, especially complex, monolithic heat exchange devices.

► Relative stiffness versus relative density measurements for reticulated mesh and stochastic open cellular copper were shown to follow the Gibson–Ashby foam model. ► Microstructures for the mesh struts and foam ligaments illustrated a propensity of copper oxide precipitates which provided structural hardness and strength. ► These components, fabricated by electron beam melting, exhibit interesting prospects for specialized, complex heat-transfer devices.