The heterogeneous microstructure in laser powder bed fabricated Inconel 718 pillar and its influence on mechanical properties

Du，Bo; Liu，Qian; He，Minglin; Yi，Jiang; He，Jing; Wang，Shuai

2023-05-08

10.1016/j.msea.2023.144953

Materials Science and Engineering A   Impact Factor & Quartile

0921-5093

1873-4936

The dimensions of small components have a strong influence on the microstructure and properties of structural material fabricated by the laser-based manufacturing approach. In this study, we analyzed the microstructure characteristics of Inconel 718 tiny pillars fabricated using laser powder bed fusion. We identified microscale heterogeneous microstructure with varying substructure sizes, arrangements of precipitates, dislocation structures, and segregation of solute atoms from the pillar center to the edge. The pillar center and edge owe very low-density dislocations, while the transition zone indicates high-density dislocation tangles on the substructure boundaries. For the first time, it is found the pillar center presents polygonal substructure with straight sub-boundaries in the absence of precipitates, which is entirely different from the typical microstructure in bulk Inconel 718 alloys manufactured using the same method. To evaluate the influence of the heterogeneous microstructure on the mechanical properties, nanoindentation and micropillar compression tests are conducted. The transition zone exhibits higher hardness and yield stress than the center and edge of the pillar. By contrast, the edge and the center region show similar mechanical responses.

Dislocation Inconel 718 alloy Laser powder bed fusion Pillar Substructure

SCI

English

First ; Corresponding

Science, Technology and Innovation Commission of Shenzhen Municipality[20220815150609002];National Key Research and Development Program of China[2022YFB4600700];Science, Technology and Innovation Commission of Shenzhen Municipality[KQTD2019092917250571];

Science & Technology - Other Topics ; Materials Science ; Metallurgy & Metallurgical Engineering

Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering

WOS:000990139700001

ELSEVIER SCIENCE SA

MATERIALS SCIENCE

2-s2.0-85151482903

Scopus

Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,1088 Xueyuan Avenue,518055,China

Du，Bo,Liu，Qian,He，Minglin,et al. The heterogeneous microstructure in laser powder bed fabricated Inconel 718 pillar and its influence on mechanical properties[J]. Materials Science and Engineering A,2023,872.

Du，Bo,Liu，Qian,He，Minglin,Yi，Jiang,He，Jing,&Wang，Shuai.(2023).The heterogeneous microstructure in laser powder bed fabricated Inconel 718 pillar and its influence on mechanical properties.Materials Science and Engineering A,872.

Du，Bo,et al."The heterogeneous microstructure in laser powder bed fabricated Inconel 718 pillar and its influence on mechanical properties".Materials Science and Engineering A 872(2023).