Microstructural Evolution of Al-1Fe (Weight Percent) Alloy During Accumulative Continuous Extrusion Forming

• Published in: Metallurgical and materials transactions. B, Process metallurgy and materials processing science Vol. 49; no. 2; pp. 490 - 498
• Main Authors: Wang, Xiang, Guan, Ren-Guo, Tie, Di, Shang, Ying-Qiu, Jin, Hong-Mei, Li, Hong-Chao
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2018; Springer Nature B.V
• Subjects: ALUMINIUM ALLOYS; ALUMINIUM COMPOUNDS; BACKSCATTERING; Characterization and Evaluation of Materials; Chemistry and Materials Science; Continuous extrusion; DEFORMATION; Deformation effects; Deformation mechanisms; Dynamic recrystallization; Electron backscatter diffraction; ELECTRON DIFFRACTION; Electron microscopy; Evolution; EXTRUSION; Forming; Fragmentation; GRAIN BOUNDARIES; GRAIN SIZE; GRANULATION; International Metallurgical Processes Workshop for Young Scholars (IMPROWYS 2017); IRON ADDITIONS; MATERIALS SCIENCE; Metallic Materials; Metallurgy; Microstructure; Nanotechnology; PARTICLES; RECRYSTALLIZATION; REFINING; Spheroidizing; Structural Materials; Surfaces and Interfaces; TEMPERATURE DEPENDENCE; Thin Films; Topical Collection: Metallurgical Processes Workshop for Young Scholars; TRANSMISSION ELECTRON MICROSCOPY; Entire Deformation Process; Electron Backscatter Diffraction (EBSD); Al-Fe Phase; Al3Fe Particles; Low-angle Grain Boundaries (LAGBs)
• ISSN: 1073-5615; 1543-1916
• DOI: 10.1007/s11663-018-1185-z

As a new microstructure refining method, accumulative continuous extrusion forming (ACEF) cannot only refine metal matrix but also refine the phases that exist in it. In order to detect the refinements of grain and second phase during the process, Al-1Fe (wt pct) alloy was processed by ACEF, and the microstructural evolution was analyzed by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Results revealed that the average grain size of Al-1Fe (wt pct) alloy decreased from 13 to 1.2  μ m, and blocky Al 3 Fe phase with an average length of 300 nm was granulated to Al 3 Fe particle with an average diameter of 200 nm, after one pass of ACEF. Refinement of grain was attributed to continuous dynamic recrystallization (CDRX), and the granulation of Al 3 Fe phase included the spheroidization resulting from deformation heat and the fragmentation caused by the coupling effects of strain and thermal effect. The spheroidization worked in almost the entire deformation process, while the fragmentation required strain accumulation. However, fragmentation contributed more than spheroidization. Al 3 Fe particle stimulated the formation of substructure and retarded the migration of recrystallized grain boundary, but the effect of Al 3 Fe phase on refinement of grain could only be determined by the contrastive investigation of Al-1Fe (wt pct) alloy and pure Al.