Additive manufacturing of steel-copper functionally graded material with ultrahigh bonding strength

Additive manufacturing enables processing of functionally graded materials (FGMs) with flexible spatial design and high bonding strength. A steel-copper FGM with high interfacial strength was developed using laser powder bed fusion (LPBF). The effect of laser process parameters on interfacial defects was evaluated by X-ray tomography, which indicates a low porosity level of 0.042 % therein. Gradient/fine dendritic grains in the interface are incited by high cooling rates, which facilitates interface strengthening. Multiple mechanical tests evaluate the bonding reliability of interface; and the fatigue tests further substantiate the ultrahigh bonding strength in FGMs, which is superior to traditional manufacturing methods. Mechanisms of the high interfacial bond strength were also discussed. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

Additive manufacturing technology is used to process functionally graded materials with high bonding strength, as demonstrated by the successful development of a steel-copper FGM using laser powder bed fusion. X-ray tomography was used to evaluate the low porosity level and the fine dendritic grains in the interface, which contribute to the high interfacial strength. Mechanical and fatigue tests confirmed the ultrahigh bonding strength in FGMs, surpassing that of traditional manufacturing methods, with discussion on the mechanisms involved.