TY - JOUR
T1 - Building orientation-structure-property in laser powder bed fusion of NiTi shape memory alloy
AU - Nematollahi, Mohammadreza
AU - Saghaian, Sayed Ehsan
AU - Safaei, Keyvan
AU - Bayati, Parisa
AU - Bassani, Paola
AU - Biffi, Carlo
AU - Tuissi, Ausonio
AU - Karaca, Haluk
AU - Elahinia, Mohammad
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/8/25
Y1 - 2021/8/25
N2 - This study is the first study on the compressive and tensile stress-strain revealing the deformation anisotropy among laser powder bed fusion NiTi parts fabricated with the same process conditions. We investigated the effects of building orientation on the microstructure and the resulting shape memory properties. To this end, three orientations were selected, namely 0, 45, and 90-degree, measured from the build plate and fabricated with the same process parameters. A strong (001) texture was formed along the building direction for all of the samples; a different texture could however be observed along the loading direction (LD). Samples fabricated with 45-degree showed a texture of (110) along the LD, as confirmed through X-ray diffraction and backscattered diffraction while 0 and 90 samples still had the (001) texture along with the LD. These texture variations created anisotropic compression-tension behaviors with deformation patterns consistent with single crystals. The (001) -textured parts showed higher strength and lower transformation strain (2.87% @ 200 MPa in tension for 0 ͦ) while the (110) samples showed higher transformation strain at lower stresses (5.31% @ 150 MPa in tension for 45 ͦ).
AB - This study is the first study on the compressive and tensile stress-strain revealing the deformation anisotropy among laser powder bed fusion NiTi parts fabricated with the same process conditions. We investigated the effects of building orientation on the microstructure and the resulting shape memory properties. To this end, three orientations were selected, namely 0, 45, and 90-degree, measured from the build plate and fabricated with the same process parameters. A strong (001) texture was formed along the building direction for all of the samples; a different texture could however be observed along the loading direction (LD). Samples fabricated with 45-degree showed a texture of (110) along the LD, as confirmed through X-ray diffraction and backscattered diffraction while 0 and 90 samples still had the (001) texture along with the LD. These texture variations created anisotropic compression-tension behaviors with deformation patterns consistent with single crystals. The (001) -textured parts showed higher strength and lower transformation strain (2.87% @ 200 MPa in tension for 0 ͦ) while the (110) samples showed higher transformation strain at lower stresses (5.31% @ 150 MPa in tension for 45 ͦ).
KW - Additive manufacturing
KW - Build orientation
KW - LPBF
KW - Shape memory alloy
KW - Texture
KW - Thermomechanical behavior
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U2 - 10.1016/j.jallcom.2021.159791
DO - 10.1016/j.jallcom.2021.159791
M3 - Article
AN - SCOPUS:85104364375
SN - 0925-8388
VL - 873
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
M1 - 159791
ER -