High strength and rapid solution Mg alloy by adding Fe element fabricated by binder jetting additive manufacturing

Abstract

The effects of Fe addition on the mechanical properties and corrosion behaviors of AZ91D alloys prepared by binder jetting additive manufacturing have been investigated. The results show that the constitution of the second phase is large dependence on Fe content. With the Fe content increasing, the second phase can transform AlFe phase to Fe and AlFe phase. In addition, with increasing Fe content, the content of second phase increases gradually, while the content of pores also increases. We believe that with the Fe content increasing, the content of second phase with Fe element increases which the melt temperature is higher than sintering temperature, and the content of liquid phase decreases, that leading the high-viscosity liquid alloy cannot fill the pores fully and the more pores will remain and causes the relative density reduces. The compressive strength shows a parabola relationship with Fe content. Furthermore, adding Fe can accelerate the degradation of Mg alloys owing to the galvanic corrosion. The sample with 5 wt% Fe content shows the highest ultimate compressive strength (440 MPa) and fast degradation rate (9091 mm/Y), which meets the soluble Mg alloy with rare earth but cost much lower.