Laser additive manufactured high-performance Fe-based composites with unique strengthening structure

Hongyu Chen ¹Dongdong Gu ²Liang Deng ³Tiwen Lu ³Uta Kühn ³Konrad Kosiba³

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作者信息

1. College of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Jiangsu Provincial Engineering Laboratory for Laser Additive Manufacturing of High-Performance Metallic Components,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Leibniz IFW Dresden,Institute for Complex Materials,P.O.Box 270116,D-01069 Dresden,Germany
2. College of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Jiangsu Provincial Engineering Laboratory for Laser Additive Manufacturing of High-Performance Metallic Components,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China
3. Leibniz IFW Dresden,Institute for Complex Materials,P.O.Box 270116,D-01069 Dresden,Germany
折叠

Abstract

Steel matrix composites (SMCs),reinforced by ceramic particles,have received a consistent attention in recent years.Using conventional methods to prepare SMCs is generally challenging,and the mechanical properties of conventionally fabricated SMCs are limited.In this study,we successfully fabricated high-performance SMCs by laser powder bed fusion (LPBF) of a composite powder consisting of Fe-based alloy powder and submicron-sized WC particles.The effect of laser energy density on the phase formation,microstructural evolution,overall density and resulting mechanical properties of LPBF-fabricated com-posites was investigated.The present results show that a novel Fe2W4C carbidic network precipitates in the solidified microstructure entailing segregations along the boundaries of cellular sub-grains.The presence of this carbidic network hampers the growth of sub-grains even at elevated temperatures,and hence,stabilizes the grain size though prepared at a broad range of different energy densities.The exact distribution of the Fe2W4C carbides depends on the employed laser energy densities,as for instance they are more uniformly distributed at higher energy input.The density of LPBF samples reaches the maxi-mum value of 99.4 ％ at 150J/mm3.In this parameter set,high microhardness of ～753 HV,compression strength of ～3350 MPa and fracture strain of ～24.4 ％ are obtained.The enhanced mechanical properties are ascribed to less metallurgical defects,higher volume fraction of the martensitic phase and increasing pile-up dislocations resulting from the pinning effect by Fe2W4C carbide.

Key words

Laser additive manufacturing/Laser powder bed fusion/Steel matrix composite/Microstructures/Mechanical properties

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基金项目

National Natural Science Foundation of China(51735005)

Basic Strengthening Program of Science and Technology(2019-JCJQ-JJ-331)

5th Jiangsu Province 333 High Level Talents Training Project(BRA2019048)

15th Batch of "Six Talents Peaks"Innovative Talents Team Program(TD-GDZB-001)

2017 Excellent Scientific and Technological Innovation Teams of Universities in Jiangsu "Laser Additive Manufacturing Technologi(51921003)

Konrad Kosiba acknowledges the support from DFG(KO 5771/1-1)

出版年

2021

材料科学技术(英文版)

中国金属学会中国材料研究学会中国科学院金属研究所

材料科学技术(英文版)

CSTPCDCSCDSCI

影响因子：0.657

ISSN：1005-0302

参考文献量44

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