We report on the microstructure and the strengthening mechanisms of additively manufactured parts fab-ricated by directed energy deposition of Ti-6Al-4V(Ti64)powders blended with yttria-stabilized zirconia(YSZ)nanoparticles.These specimens showed refined microstructures as compared to bare as-deposited Ti64,where the α and columnar prior β grain sizes decreased with increasing YSZ content.The YSZ nanoparticles decomposed during the deposition process and led to the formation of yttrium oxide and some excess oxygen in the Ti64 matrix.The decrease in the sizes of the prior β grains could be attributed to the increasing amount of dissolved oxygen and yttrium,which promoted constitutional supercooling.Furthermore,the reduction in the size of the α grains could be ascribed to a shift of the onset of theβ→α+β transformation to a higher temperature and shorter time with increasing concentration of dis-solved oxygen.Finally,the contributions of the underlying strengthening mechanisms for the as-deposited specimens were quantitatively determined.

Gwanghyo Choi;Won Seok Choi;Yoon Sun Lee;Dahye Kim;Ji Hyun Sung;Seungjun An;Chang-Seok Oh;Amine Hattal;Madjid Djemai;Brigitte Bacroix;Guy Dirras;Pyuck-Pa Choi

Department of Materials Science and Engineering,Korea Advanced Institute of Science and Technology,Daejeon 34141,Republic of Korea;3D Additive Manufacturing Application Tech.Center,Korea Institute of Industrial Technology,Daegu 42994,Republic of Korea;InssTek Co.,Daejeon 04763,Republic of Korea;Korea Institute of Materials Science,797 Changwondaero,Changwon 51508,Republic of Korea;Université Sorbonne Paris Nord,Laboratoire des Sciences des Procédés et des Matériaux,LSPM,CNRS,UPR 3407,F-93430,Villetaneuse,France;Z3Dlab,Parc Technologique,26 Rue des Sablons,Montmagny 95360,France;CNRS,UPR3407,Laboratoire des Sciences des Procédés et des Matériaux,LSPM,Université Sorbonne Paris Nord,F-93430,Villetaneuse,France

材料科学技术（英文版）

[1]Gwanghyo Choi;Won Seok Choi;Yoon Sun Lee;Dahye Kim;Ji Hyun Sung;Seungjun An;Chang-Seok Oh;Amine Hattal;Madjid Djemai;Brigitte Bacroix;Guy Dirras;Pyuck-Pa Choi-.Decomposition behavior of yttria-stabilized zirconia and its effect on directed energy deposited Ti-based composite material)[J].材料科学技术（英文版）,2022(17):138-150

Decomposition,behavior,yttria,stabilized,zirconia,its,effect,directed,energy,deposited,composite,material,We,report,strengthening,mechanisms,additively,manufactured,parts,fab,ricated,by,deposition,6Al,4V,Ti64,powders,blended,YSZ,nanoparticles,These,specimens,showed,refined,microstructures,compared,bare,where,columnar,prior,sizes,decreased,increasing,content,decomposed,during,process,led,yttrium,oxide,some,excess,oxygen,matrix,grains,could,attributed,amount,dissolved,which,promoted,constitutional,supercooling,Furthermore,reduction,ascribed,shift,onset,transformation,higher,temperature,shorter,concentration,Finally,contributions,underlying,were,quantitatively,determined

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