Novel approach to additively manufacture high-strength Al alloys by laser powder bed fusion through addition of hybrid grain refiners

Li，Xinwei1; Li，Gan1; Zhang，Ming Xing2; Zhu，Qiang1

2021-12-01

10.1016/j.addma.2021.102400

Additive Manufacturing   影响因子和分区

2214-8604

2214-8604

Grain refinement is effective in restraining hot tearing, reducing anisotropy, eliminating defects, improving processability, and enhancing the mechanical properties of high-strength aluminum components additively manufactured by laser powder bed fusion (LPBF). However, achieving the desired strength and ductility in LPBF-fabricated high-strength aluminum alloys post grain refinement is a predominant challenge. We have therefore designed and developed a novel hybrid grain refiner (solute/ceramic nanoparticles) which can effectively refine grains and enhance the mechanical properties of LPBF-fabricated high-strength aluminum alloys. Adding a Ti/TiN hybrid grain refiner to the LPBF-fabricated 7050 alloy can produce ultrafine grains with an average size of 775 nm, resulting in an ultimate tensile strength and ductility of up to 408–618 MPa and 13.2–8.8%, respectively. These tensile properties are comparable to those of conventional wrought 7XXX alloys. During LPBF processing, the hybrid grain refiner exhibited interesting synergistic grain refinements and strengthening mechanisms between the solute and the ceramic nanoparticles. During solidification, not only in-situ particles formed by the chemical reaction of the solute in liquid Al and the externally added ceramic nanoparticles can act as the nuclei of α-Al respectively, but also solute can inhibit the agglomeration of ceramic nanoparticles to promote their nucleation efficiency. Moreover, the strength can be further improved by doping the solute atoms at the ceramic nanoparticle/Al interface. The improvement in elongation benefited from the uniform dispersion of the various particles.

Additive manufacturing Aluminum alloys Grain refinement Solidification Strengthening

SCI ; EI

英语

第一 ; 通讯

National Natural Science Foundation of China[51801096] ; Shenzhen Science and Technology Project["JCYJ20180305123432756","KQTD20170328154443162"] ; Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials[ZDSYS201703031748354]

Engineering ; Materials Science

Engineering, Manufacturing ; Materials Science, Multidisciplinary

WOS:000719274700002

ELSEVIER

20214511116620

3D printers ; Additives ; Aluminum alloys ; Ductility ; Grain size and shape ; High strength alloys ; Nanoparticles ; Refining ; Solidification ; Tensile strength

Metallurgy:531.1 ; Aluminum Alloys:541.2 ; Printing Equipment:745.1.1 ; Nanotechnology:761 ; Chemical Operations:802.3 ; Chemical Agents and Basic Industrial Chemicals:803 ; Solid State Physics:933 ; Materials Science:951

2-s2.0-85118491428

Scopus

1.Department of Mechanical and Energy Engineering,Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials,Southern University of Science and Technology,Shenzhen,518055,China
2.School of Mechanical and Mining Engineering,The University of Queensland,St. Lucia,4072,Australia

Li，Xinwei,Li，Gan,Zhang，Ming Xing,et al. Novel approach to additively manufacture high-strength Al alloys by laser powder bed fusion through addition of hybrid grain refiners[J]. Additive Manufacturing,2021,48.

Li，Xinwei,Li，Gan,Zhang，Ming Xing,&Zhu，Qiang.(2021).Novel approach to additively manufacture high-strength Al alloys by laser powder bed fusion through addition of hybrid grain refiners.Additive Manufacturing,48.

Li，Xinwei,et al."Novel approach to additively manufacture high-strength Al alloys by laser powder bed fusion through addition of hybrid grain refiners".Additive Manufacturing 48(2021).