Conventional cast Al-Ce alloys are challenged by the increasing demand for improved mechanical properties.To address this issue,in this study,wire-arc directed energy deposition(WA-DED)is employed for the fabrication ...Conventional cast Al-Ce alloys are challenged by the increasing demand for improved mechanical properties.To address this issue,in this study,wire-arc directed energy deposition(WA-DED)is employed for the fabrication of Al-15Ce-3Mg(wt%)alloy components.We aimed to tune the microstructure and mechanical properties via the inherent sub-rapid-solidification effect of WA-DED.In addition to significant microstructure refinement,a decrease in arc heat input leads to a larger cooling rate,up to 346℃/s,and triggers the transition from hyper-eutectic to near-eutecticα-Al/Al_(11)Ce_(3)microstructures with the suppression of primary Al_(11)Ce_(3)intermetallics.Such microstructural modification improves the mechanical properties,resulting in higher yield and ultimate tensile strengths than those of the as-cast counterpart alloy.The fracture process involves the formation of dim-ples around Al_(11)Ce_(3),cracking of large Al_(11)Ce_(3) particles,and growth,merging,and fracture of pores.The strength increment is mainly contributed by particle-size strengthening mediated by microstructure refinement as well as the targeted formation of near-eutecticα-Al/Al_(11)Ce_(3)microstructures.展开更多
基金supported by National Natural Science Foundation of China(Grant No.52105319)The authors are grateful to the Analysis&Testing Center and the Micro-and Nanotechnology Center at the Beijing Institute of Technology for performing the XRM experiments.
文摘Conventional cast Al-Ce alloys are challenged by the increasing demand for improved mechanical properties.To address this issue,in this study,wire-arc directed energy deposition(WA-DED)is employed for the fabrication of Al-15Ce-3Mg(wt%)alloy components.We aimed to tune the microstructure and mechanical properties via the inherent sub-rapid-solidification effect of WA-DED.In addition to significant microstructure refinement,a decrease in arc heat input leads to a larger cooling rate,up to 346℃/s,and triggers the transition from hyper-eutectic to near-eutecticα-Al/Al_(11)Ce_(3)microstructures with the suppression of primary Al_(11)Ce_(3)intermetallics.Such microstructural modification improves the mechanical properties,resulting in higher yield and ultimate tensile strengths than those of the as-cast counterpart alloy.The fracture process involves the formation of dim-ples around Al_(11)Ce_(3),cracking of large Al_(11)Ce_(3) particles,and growth,merging,and fracture of pores.The strength increment is mainly contributed by particle-size strengthening mediated by microstructure refinement as well as the targeted formation of near-eutecticα-Al/Al_(11)Ce_(3)microstructures.
