摘要
The evolution of the 3D Fe-rich phases of Al-7.0Si-1.2Fe alloys with different Mn contents was visualized and characterized using synchrotron X-ray computed tomography,and the effect of Fe-rich phases with typical morphologies on the fracture behavior during tensile testing was analyzed.The results showed that the Fe-rich phase changed from platelet-likeβ-Al_(5) Fe Si intoα-Al_(15)(Fe Mn)_(3)Si_(2)with various morphologies after the addition of Mn.The Mn addition not only significantly reduced the volume fraction,equivalent diameter and interconnectivity of the Fe-rich phase but also greatly increased the sphericity,surface thickness,and distribution of the mean curvature and surface thickness.Furthermore,the equivalent diameter ofα-Al_(15)(FeMn)_(3)Si_(2)had an inverse exponential function relationship with its sphericity.The 3D morphology ofα-Al_(15)(FeMn)_(3)Si_(2)can be summarized as massive and regular polyhedrons,hollow and regular polyhedrons,and multibranched polyhedrons.The fraction of the different 3D morphologies in each alloy is related to the Mn content,where excess Mn increased the number and volume fraction of the large Fe-rich particles with a low sphericity.The ductility of each alloy was significantly improved by the addition of Mn but gradually decreased when the Mn/Fe ratio exceeded 1.2.The increase in largeα-Al_(15)(Mn Fe)_(3)Si_(2)with a low sphericity was the main reason for the decreased ductility of alloys with a high Mn content.
基金
supported by the National Natural Science Foundation of China(No.52074131)
the Foundation and Applied Foundation Program of Guangdong Province(No.2020B1515120065)
the Key-Area Research and Development Program of Guangdong Province(No.2020B010186002)
the Science and Technology Plan Program of Guangdong Province(Nos.2015B090926013,2019B090905009)
the WL13W1 beamline of Shanghai Synchrotron Radiation Facility,SSRF(proposal number 2018-SSRF-PT-006299,2020-SSRF-PT-011937)。
