Mechanical Properties and Microstructure of DMLS Ti6Al4V Alloy Dedicated to Biomedical Applications

Żaneta Anna Mierzejewska , R. Hudak , Jarosław Sidun

Abstract

The aim of this work was to investigate the microstructure and mechanical properties of samples produced by direct metal laser sintering (DMLS) with varied laser beam speed before and after heat treatment. Optical analysis of as-built samples revealed microstructure built of martensite needles and columnar grains, growing epitaxially towards the built direction. External and internal pores, un-melted or semi-melted powder particles and inclusions in the examined samples were also observed. The strength and Young’s modulus of the DMLS samples before heat treatment was higher than for cast and forged samples; however, the elongation at break for vertical and horizontal orientation was lower than required for biomedical implants. After heat treatment, the hardness of the samples decreased, which is associated with the disappearance of boundary effect and martensite decomposition to lamellar mixture of and , and the anisotropic behaviour of the material also disappears. Ultimate tensile strength (UTS) and yield strength(YS) also decreased, while elongation increased. Tensile properties were sensitive to the build orientation, which indicates that DMLS generates anisotropy of material as a result of layered production and elongated prior grains. It was noticed that inappropriate selection of parameters did not allow properties corresponding to the standards to be obtained due to the high porosity and defects of the microstructure caused by insufficient energy density.
Author Żaneta Anna Mierzejewska (FME / DBBE)
Żaneta Anna Mierzejewska,,
- Department of Biocybernetics and Biomedical Engineering
, R. Hudak
R. Hudak,,
-
, Jarosław Sidun (FME / DBBE)
Jarosław Sidun,,
- Department of Biocybernetics and Biomedical Engineering
Journal seriesMaterials, ISSN 1996-1944, (N/A 140 pkt)
Issue year2019
Vol12
No1
Pages1-17
Publication size in sheets0.85
Keywords in Englishselective laser melting, direct metal laser sintering, porous biomaterials, titanium alloys, mechanical properties
ASJC Classification2500 General Materials Science
DOIDOI:10.3390/ma12010176
URL https://www.mdpi.com/1996-1944/12/1/176
Internal identifier000044652
Languageen angielski
LicenseJournal (articles only); published final; Uznanie Autorstwa (CC-BY); with publication
Score (nominal)140
Score sourcejournalList
ScoreBUT score = 42.0, manual
Ministerial score = 140.0, 20-02-2020, ArticleFromJournal
Publication indicators Scopus SNIP (Source Normalised Impact per Paper): 2017 = 1.285; WoS Impact Factor: 2018 = 2.972 (2) - 2018=3.532 (5)
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