摘要
Developing high-strength Al-(La,Ce)alloys for additive manufacturing(AM)would entail considerable economic benefits.In this work,a novel near-eutectic Al-La alloy containing 5.50 wt.%Mg and 0.60 wt.%Mn was designed and fabricated via selective laser melting(SLM).Submicron Al_(11)La_(3)intermetallics with 3D continuous cellular-dendritic and granular morphologies were observed at the interior and boundary of the melt pool,respectively.Interestingly,these intermetallics are hierarchical and contained numerous Al_(6)Mn and Mg_(2)Si secondary nanoprecipitates.The as-fabricated alloy exhibited a tensile yield strength(YS)of 334 MPa and ultimate tensile strength(UTS)of 588 MPa at room temperature,which is the high-est UTS reported for Al-(La,Ce)alloys with an appreciable failure strain of∼6.4%.The 3D continuous cellular dendritic intermetallic and high Mg content afford significant strengthening and work harden-ing ability.In addition,the hierarchical feature of the intermetallics generated additional microcracks to coordinate the deformation.
基金
This work was financially supported by the Guangdong Natu-ral Science Foundation(No.2020A1515011242).The Shanghai Syn-chrotron Radiation Facility(SSRF)provided the synchrotron XRD facility at beamline No.14 B.Atom probe tomography research was conducted by Dr.J.H.Luan at the Inter-University 3D Atom Probe Tomography Unit of the City University of Hong Kong,supported by the CityU grant 9360161.
