Quantum mechanics

High strength steel

Adhesive

Metallurgy

Materials science

Bond strength

Layer (electronics)

Power (physics)

Bonding strength

Porosity

Physics

Reliability (semiconductor)

Composite material

Copper

Journal of Material Science and Technology

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.

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