SLM of TI-6AL-4V single melt-tracks under different layer thickness and surface roughness

The smallest feature that can be built using the selective laser melting (SLM) process is limited by the width of a single melt-track which can be minimized by lowering the laser energy input. However, melt-tracks could become unstable under low energy input due to insufficient melt pool penetrat...

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Main Authors: Tey, Cher Fu, Yeong, Wai Yee
Other Authors: School of Mechanical and Aerospace Engineering
Format: Conference Paper
Language:English
Published: 2018
Subjects:
Online Access:https://hdl.handle.net/10356/88566
http://hdl.handle.net/10220/45864
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author Tey, Cher Fu
Yeong, Wai Yee
author2 School of Mechanical and Aerospace Engineering
author_facet School of Mechanical and Aerospace Engineering
Tey, Cher Fu
Yeong, Wai Yee
author_sort Tey, Cher Fu
collection NTU
description The smallest feature that can be built using the selective laser melting (SLM) process is limited by the width of a single melt-track which can be minimized by lowering the laser energy input. However, melt-tracks could become unstable under low energy input due to insufficient melt pool penetration into the underlying layer. In this study, Ti-6Al-4V single melttracks are deposited using 3 different laser energy inputs (343, 240, 133J/m) on selected build layers starting from the sandblasted substrate on layer 1, to layer 45. The layer thickness and surface roughness (Pq) of the underlying layer progressively increase from 12±10μm to 46±24μm and 4.3±0.1μm to 25±6 μm respectively across the initial build layers. The width and continuity of the melt-tracks are measured across those layers and it is found that the track width increases with laser energy input but is not sensitive to layer thickness and the surface roughness of the underlying layer. The single melt-tracks processed with a 343J/m energy input remains continuous throughout all 45 build layers due to sufficient melt pool penetration into the underlying layer. The single melt-tracks processed under the 240J/m energy input is continuous from layers 1-7 but breaks up into discontinuous tracks from layer 9 onward when the layer thickness and surface roughness (Pq) exceeds 42±17μm and 17±2μm respectively. The single melt-tracks processed under 133J/m energy input is continuous on layer 1, discontinuous from layers 3-5, and undergoes complete “balling” from layer 7 onward where the layer thickness and surface roughness (Pq) exceeds 36±17μm and 18±2μm respectively. It is shown that the smallest printable feature, which corresponds to the width of a single melt-track, is mainly affected by the laser energy input while the continuity of such melt-tracks is maintained by limiting the layer thickness and surface roughness to sufficiently small values.
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spelling ntu-10356/885662020-09-24T20:13:02Z SLM of TI-6AL-4V single melt-tracks under different layer thickness and surface roughness Tey, Cher Fu Yeong, Wai Yee School of Mechanical and Aerospace Engineering Proceedings of the 3rd International Conference on Progress in Additive Manufacturing (Pro-AM 2018) Singapore Centre for 3D Printing SLM Ti-6Al-4V DRNTU::Engineering::Mechanical engineering::Prototyping The smallest feature that can be built using the selective laser melting (SLM) process is limited by the width of a single melt-track which can be minimized by lowering the laser energy input. However, melt-tracks could become unstable under low energy input due to insufficient melt pool penetration into the underlying layer. In this study, Ti-6Al-4V single melttracks are deposited using 3 different laser energy inputs (343, 240, 133J/m) on selected build layers starting from the sandblasted substrate on layer 1, to layer 45. The layer thickness and surface roughness (Pq) of the underlying layer progressively increase from 12±10μm to 46±24μm and 4.3±0.1μm to 25±6 μm respectively across the initial build layers. The width and continuity of the melt-tracks are measured across those layers and it is found that the track width increases with laser energy input but is not sensitive to layer thickness and the surface roughness of the underlying layer. The single melt-tracks processed with a 343J/m energy input remains continuous throughout all 45 build layers due to sufficient melt pool penetration into the underlying layer. The single melt-tracks processed under the 240J/m energy input is continuous from layers 1-7 but breaks up into discontinuous tracks from layer 9 onward when the layer thickness and surface roughness (Pq) exceeds 42±17μm and 17±2μm respectively. The single melt-tracks processed under 133J/m energy input is continuous on layer 1, discontinuous from layers 3-5, and undergoes complete “balling” from layer 7 onward where the layer thickness and surface roughness (Pq) exceeds 36±17μm and 18±2μm respectively. It is shown that the smallest printable feature, which corresponds to the width of a single melt-track, is mainly affected by the laser energy input while the continuity of such melt-tracks is maintained by limiting the layer thickness and surface roughness to sufficiently small values. NRF (Natl Research Foundation, S’pore) Published version 2018-09-06T06:51:05Z 2019-12-06T17:06:15Z 2018-09-06T06:51:05Z 2019-12-06T17:06:15Z 2018 Conference Paper Tey, C. F., & Yeong, W. Y. (2018). SLM of TI-6AL-4V single melt-tracks under different layer thickness and surface roughness. Proceedings of the 3rd International Conference on Progress in Additive Manufacturing (Pro-AM 2018), 347-352. doi:10.25341/D4C880 https://hdl.handle.net/10356/88566 http://hdl.handle.net/10220/45864 10.25341/D4C880 en © 2018 Nanyang Technological University. Published by Nanyang Technological University, Singapore. 6 p. application/pdf
spellingShingle SLM
Ti-6Al-4V
DRNTU::Engineering::Mechanical engineering::Prototyping
Tey, Cher Fu
Yeong, Wai Yee
SLM of TI-6AL-4V single melt-tracks under different layer thickness and surface roughness
title SLM of TI-6AL-4V single melt-tracks under different layer thickness and surface roughness
title_full SLM of TI-6AL-4V single melt-tracks under different layer thickness and surface roughness
title_fullStr SLM of TI-6AL-4V single melt-tracks under different layer thickness and surface roughness
title_full_unstemmed SLM of TI-6AL-4V single melt-tracks under different layer thickness and surface roughness
title_short SLM of TI-6AL-4V single melt-tracks under different layer thickness and surface roughness
title_sort slm of ti 6al 4v single melt tracks under different layer thickness and surface roughness
topic SLM
Ti-6Al-4V
DRNTU::Engineering::Mechanical engineering::Prototyping
url https://hdl.handle.net/10356/88566
http://hdl.handle.net/10220/45864
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