Abstract
Aβ-type Ti-41Nb alloy with high relative density has been successfully fabricated by laser powder bed fusion(L-PBF)using pre-alloyed powders for potential implant application.The homogeneous microstruc-ture can be achieved in L-PBF fabricated(L-PBFed)Ti-41Nb alloy but slight composition segregation was detected along molten pool boundaries.The L-PBFed alloy was dominated by typical epitaxial columnar grains with strong<001>grain orientation along building direction(BD),and cellular structure was dis-tinguished within the columnar grains.The main reasons for this microstructure can be attributed to effective thermal gradient and epitaxial growth.L-PBFed alloy exhibited higher mechanical strength com-pared with cold rolling plus annealing(CRA)alloy due to the finer grains,dislocations accumulation and different TRIP behaviors,accompanied by good ductility.It also exhibited much lower thermal conductiv-ity and better hydrophilic feature than those of CP-Ti.Besides,the L-PBFed alloy exhibited slightly better cell spread and cell proliferation rates compared with CP-Ti.Moreover,L-PBFed alloy presented better alkaline phosphatase(ALP)activities and extracellular matrix(ECM)mineralization,which suggests that the L-PBFed alloy can stimulate the osteogenic differentiation of rat bone mesenchymal stem cells.The Ti-41Nb alloy,fabricated by L-PBF,reveals a good combination of mechanical properties,physicochemical properties and biocompatibility,exhibiting the great potential as the dental implant.
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