Ductility of a Ti‐6Al‐4V alloy produced by selective laser melting of prealloyed powders

Purpose – The aim of the paper is the study of the change in the mechanical properties (and in particular in ductility), with the microstructure, of a biomedical Ti‐6Al‐4V alloy produced by different variants of selective laser melting (SLM).Design/methodology/approach – Ti‐6Al‐4V alloy produced by different variants of SLM has been mechanically characterized through tensile testing. Its microstructure has been investigated by optical observation after etching and by X‐ray diffraction analysis.Findings – SLM applied to Ti‐6Al‐4V alloy produces a material with a martensitic microstructure. Some microcracks, due the effect of incomplete homologous wetting and residual stresses produced by the large solidification undercooling of the melt pool, are observable in the matrix. Owing to the microstructure, the tensile strength of the additive manufactured parts is higher than the strength of hot worked parts, whereas the ductility is lower. A pre‐heating of the powder bed is effective in assisting remelting and ...

[1]  J. Beaman,et al.  Powder densification maps in selective Laser Sintering , 2002 .

[2]  L. Froyen,et al.  Selective laser melting of iron-based powder , 2004 .

[3]  M. A. Mannan,et al.  Rapid prototyping and rapid manufacturing in medicine and dentistry , 2011 .

[4]  E. W. Collings,et al.  The physical metallurgy of titanium alloys , 1984 .

[5]  Jan Sieniawski,et al.  Development of the microstructure and fatigue strength of two phase titanium alloys in the processes of forging and heat treatment , 1998 .

[6]  Luca Facchini,et al.  Microstructure and mechanical properties of Ti‐6Al‐4V produced by electron beam melting of pre‐alloyed powders , 2009 .

[7]  M. von Walter,et al.  Structural, mechanical and in vitro characterization of individually structured Ti-6Al-4V produced by direct laser forming. , 2006, Biomaterials.

[8]  C. V. van Blitterswijk,et al.  Porous Ti6Al4V scaffold directly fabricating by rapid prototyping: preparation and in vitro experiment. , 2006, Biomaterials.

[9]  J. Planell,et al.  Influence of tempering temperature and time on the α′-Ti-6Al-4V martensite , 1996 .

[10]  S. Zec,et al.  The effect of annealing temperatures and cooling rates on microstructure and mechanical properties of investment cast Ti–6Al–4V alloy , 2006 .

[11]  A. Mitchell.  The electron beam melting and refining of titanium alloys , 1999 .

[12]  S. Das.  Physical Aspects of Process Control in Selective Laser Sintering of Metals , 2003 .

[13]  Emeka Nkenke,et al.  Effects of topographical surface modifications of electron beam melted Ti-6Al-4V titanium on human fetal osteoblasts. , 2008, Journal of biomedical materials research. Part A.

[14]  A. Long,et al.  Synchrotron X-ray diffraction study of the phase transformations in titanium alloys , 2002 .

[15]  Ola L. A. Harrysson,et al.  Characterization of H13 steel produced via electron beam melting , 2004 .

[16]  Abdolreza Simchi,et al.  Effects of laser sintering processing parameters on the microstructure and densification of iron powder , 2003 .

[17]  S. Semiatin,et al.  Prediction of the kinetics of static globularization of Ti-6Al-4V , 2005 .