Abstract
Heterogeneous grain structure is a source of the inhomogeneity in structure and properties of the metallic components made by multi-layer additive manufacturing (AM). During AM, repeated heating and cooling during multi-layer deposition, local temperature gradient and solidification growth rate, deposit geometry, and molten pool shape and size govern the evolution of the grain structure. Here the effects of these causative factors on the heterogeneous grain growth during multi-layer laser deposition of Inconel 718 are examined by a Monte Carlo method based grain growth model. It is found that epitaxial columnar grain growth occurs from the substrate or previously deposited layer to the curved top surface of the deposit. The growth direction of these columnar grains is controlled by the molten pool shape and size. The grains in the previously deposited layers continue to grow because of the repeated heating and cooling during the deposition of the successive layers. Average longitudinal grain area decreases by approximately 80% when moving from the center to the edge of the deposit due to variable growth directions dependent on the local curvatures of the moving molten pool. The average horizontal grain area increases with the distance from the substrate, with a 20% increase in the horizontal grain area in a short distance from the third to the eighth layer, due to competitive solid-state grain growth causes increased grain size in previous layers.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 448-459 |
| Number of pages | 12 |
| Journal | Additive Manufacturing |
| Volume | 25 |
| DOIs | |
| State | Published - Jan 1 2019 |
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All Science Journal Classification (ASJC) codes
- Biomedical Engineering
- Materials Science(all)
- Engineering (miscellaneous)
- Industrial and Manufacturing Engineering
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Three-dimensional grain growth during multi-layer printing of a nickel-based alloy Inconel 718. / Wei, H. L.; Knapp, G. L.; Mukherjee, T.; Debroy, Tarasankar.
In: Additive Manufacturing, Vol. 25, 01.01.2019, p. 448-459.Research output: Contribution to journal › Article
TY - JOUR
T1 - Three-dimensional grain growth during multi-layer printing of a nickel-based alloy Inconel 718
AU - Wei, H. L.
AU - Knapp, G. L.
AU - Mukherjee, T.
AU - Debroy, Tarasankar
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Heterogeneous grain structure is a source of the inhomogeneity in structure and properties of the metallic components made by multi-layer additive manufacturing (AM). During AM, repeated heating and cooling during multi-layer deposition, local temperature gradient and solidification growth rate, deposit geometry, and molten pool shape and size govern the evolution of the grain structure. Here the effects of these causative factors on the heterogeneous grain growth during multi-layer laser deposition of Inconel 718 are examined by a Monte Carlo method based grain growth model. It is found that epitaxial columnar grain growth occurs from the substrate or previously deposited layer to the curved top surface of the deposit. The growth direction of these columnar grains is controlled by the molten pool shape and size. The grains in the previously deposited layers continue to grow because of the repeated heating and cooling during the deposition of the successive layers. Average longitudinal grain area decreases by approximately 80% when moving from the center to the edge of the deposit due to variable growth directions dependent on the local curvatures of the moving molten pool. The average horizontal grain area increases with the distance from the substrate, with a 20% increase in the horizontal grain area in a short distance from the third to the eighth layer, due to competitive solid-state grain growth causes increased grain size in previous layers.
AB - Heterogeneous grain structure is a source of the inhomogeneity in structure and properties of the metallic components made by multi-layer additive manufacturing (AM). During AM, repeated heating and cooling during multi-layer deposition, local temperature gradient and solidification growth rate, deposit geometry, and molten pool shape and size govern the evolution of the grain structure. Here the effects of these causative factors on the heterogeneous grain growth during multi-layer laser deposition of Inconel 718 are examined by a Monte Carlo method based grain growth model. It is found that epitaxial columnar grain growth occurs from the substrate or previously deposited layer to the curved top surface of the deposit. The growth direction of these columnar grains is controlled by the molten pool shape and size. The grains in the previously deposited layers continue to grow because of the repeated heating and cooling during the deposition of the successive layers. Average longitudinal grain area decreases by approximately 80% when moving from the center to the edge of the deposit due to variable growth directions dependent on the local curvatures of the moving molten pool. The average horizontal grain area increases with the distance from the substrate, with a 20% increase in the horizontal grain area in a short distance from the third to the eighth layer, due to competitive solid-state grain growth causes increased grain size in previous layers.
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U2 - 10.1016/j.addma.2018.11.028
DO - 10.1016/j.addma.2018.11.028
M3 - Article
AN - SCOPUS:85057553965
VL - 25
SP - 448
EP - 459
JO - Additive Manufacturing
JF - Additive Manufacturing
SN - 2214-8604
ER -