Abstract
The microstructural factors contributing to the high strength of additive-manufactured Al-Si alloys us-ing laser-beam powder bed fusion(PBF-LB)were identified by in-situ synchrotron X-ray diffraction in tensile deformation and transmission electron microscopy.PBF-LB and heat treatment were employed to manufacture Al-12％Si binary alloy specimens with different microstructures.At an early stage of de-formation prior to macroscopic yielding,stress was dominantly partitioned into the α-Al matrix,rather than the Si phase in all specimens.Highly concentrated Si solute(～3％)in the α-Al matrix promoted the dynamic precipitation of nanoscale Si phase during loading,thereby increasing the yield strength.After macroscopic yielding,the partitioned stress in the Si phase monotonically increased in the strain-hardening regime with an increase in the dislocation density in the α-Al matrix.At a later stage of strain hardening,the flow curves of the partitioned stress in the Si phase yielded stress relaxation owing to plastic deformation.Therefore,Si-phase particles localized along the cell walls in the cellular-solidified microstructure play a significant role in dislocation obstacles for strain hardening.Compared with the results of the heat-treated specimens with different microstructural factors,the dominant strengthening factors of PBF-LB manufactured Al-Si alloys were discussed.
基金项目
JST PRESTO(JP-MJPR22Q4)
Light Metal Educational Foundation,Inc.(Japan)()
"Knowledge Hub Aichi"Aichi Prefectural Government(Japan)()
synchrotron radiation experiments were performed at BL46XUof Spring-8with the approval of the Japan Synchrotron Radiation Re(2021A1663)
synchrotron radiation experiments were performed at BL46XUof Spring-8with the approval of the Japan Synchrotron Radiation Re(2022A1001)
synchrotron radiation experiments were performed at BL46XUof Spring-8with the approval of the Japan Synchrotron Radiation Re(2022A1798)
NETL
NSTL
万方数据