Steel-copper functionally graded material produced by twin-wire and arc additive manufacturing (T-WAAM)

In this work, a functionally graded material (FGM) part was fabricated by depositing Cu-based alloy on top of high strength low (HSLA) steel twin-wire and arc additive manufacturing (T-WAAM). Copper parts are interest in many industries since they can combine thermal/electrical conductivity, wear resistance with excellent mechanical properties. However, mixing copper is difficult due to mismatches the coefficient thermal expansion, melting temperature, crystal structure. Moreover, existence miscibility gap during solidification, when melt undercooled, causes serious phase separation segregation solidification which greatly affects control samples specimen were investigated using optical microscopy, scanning electron energy synchrotron X-ray diffraction. Retained δ-ferrite found Cu matrix at interface region regions mixed composition. A smooth gradient hardness electric conductivity along FGM sample height obtained. An ultimate tensile 690 MPa an elongation fracture 16.6% measured part.