Ti/Al dissimilar metals fabricated by cold metal transfer additive manufacturing

Dissimilar alloys component was fabricated using TC4 and ER2319 wires by direct/variable polarity cold metal transfer. Microstructure and mechanical properties of Ti/Al component were analyzed by optical microscope, scanning electron microscope, transmission electron microscopy, energy dispersive X-ray spectrometer, nanoindentation, microhardness test and tensile test. The results shown that minute Ti alloy was melted when Al alloy was deposited on the surface of Ti alloy. Ti atoms diffused to liquid Al alloy and the long strip TiAl₃ phases were formed with difference length. The reaction layer about 10 μm in thickness was formed at the Ti/Al interface. The reaction layer near the Ti alloy side was continuous. The reaction layer near the Al alloy was long strip or block shape. The microhardness of reaction layer was between Al alloy and Ti alloy. The maximum tensile strength of the component was 111 MPa. Fracture occurred in the Ti/Al reaction layer for all samples.