Microstructure and mechanical properties of wire and arc additive manufactured Ti-6Al-4V and AlSi5 dissimilar alloys using cold metal transfer welding

Ti-6Al-4V and AlSi5 wires were used for wire and arc additive manufacturing using the direct current cold metal transfer welding. Ti alloy was deposited first, and then Al alloy was deposited on the Ti layer. A small amount of Ti alloy was melted when the first layer of Al alloy was deposited due to the low heat input. A component composed of Ti/Al dissimilar alloys can be produced. The interface layer between the Ti and Al alloys included a continuous layer and a discontinuous layer. The continuous layer was composed of Ti7Al5Si12, and the discontinuous layer consisted of Ti(Al1-xSix)(3). Element Si was rich in the continuous layer. The hardness and modulus of the interface layer were between those of Al and Ti alloys. The average tensile strength of the component was 79 MPa. The fracture located at the interface layer.