| 摘 要： | Ti-Ta alloys have been widely studied for biomedical applications due to their high biocompatibility and corrosion resistance.In this work,nearly fully dense and in situ alloyed Ti-50 wt% Ta samples were fabricated by the laser powder bed fusion(LPBF) of mechanically mixed powders.With increased exposure time,and thereby increased laser energy density,insoluble Ta particles were almost dissolved,and a Ti-50 wt% Ta alloy was formed.Cellular and dendritic structures were formed due to constitutional undercooling,which was caused by the high cooling rate of LPBF process.Both retained βphases and α phases were observed in the LPBFed Ti-50 wt% Ta alloy.The α phase was found at the boundary of the cellular structures,where the tantalum content was not high enough to suppress the bcc lattice transition completely but could suppress the β phase→α' phase transition.
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