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Title: Effects of Forging Process Parameters on Microstructure Evolution of Aluminum Alloy 7050

Abstract

The objective of this work is to investigate the behavior of microstructure evolution of aluminum alloy 7050 under the condition of different forging process parameters by means of combining materials physical model with finite element code. For the purpose of establishing constitutive equation and physical model of microstructure evolution, the isothermal compression test were performed by machine Gleeble 1500 on the condition of temperatures ranging from 250 deg. C to 450 deg. C and constant strain rates of 0.01s-1, 0.1s-1, 1s-1 and 10s-1. The behaviors of microstructure evolutions of aluminum alloy 7050 under difference process parameters were studied by metallographic observations. The experiment results showed that recrystallization during forming process occurred at the critical strain and the volume fraction of recrystallization changed with the temperature and strain rate. According to the results of isothermal compression test, a constitutive equation and an empirical model of DRX were obtained. A finite element code DEFORM 3D was used to analyze the influence of different forging process parameters on the behavior of microstructure evolution in details. The present model and simulation method can be served as a useful tool to predict and control the properties and shape of aluminum alloy 7050 components during forging.

Authors:
; ; ;  [1]
  1. School of Mechanical and Electrical Engineering, Central South University, 410083 Changsha (China)
Publication Date:
OSTI Identifier:
21057052
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 907; Journal Issue: 1; Conference: 10. ESAFORM conference on material forming, Zaragoza (Spain), 18-20 Apr 2007; Other Information: DOI: 10.1063/1.2729559; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM ALLOYS; COMPRESSION; COMPUTERIZED SIMULATION; CRYSTAL STRUCTURE; D CODES; FINITE ELEMENT METHOD; FORGING; METALLOGRAPHY; MICROSTRUCTURE; RECRYSTALLIZATION; STRAIN RATE; STRAINS

Citation Formats

Yi Youping, Shi Yan, Yang Jihui, and Lin Yongcheng. Effects of Forging Process Parameters on Microstructure Evolution of Aluminum Alloy 7050. United States: N. p., 2007. Web. doi:10.1063/1.2729559.
Yi Youping, Shi Yan, Yang Jihui, & Lin Yongcheng. Effects of Forging Process Parameters on Microstructure Evolution of Aluminum Alloy 7050. United States. doi:10.1063/1.2729559.
Yi Youping, Shi Yan, Yang Jihui, and Lin Yongcheng. Sat . "Effects of Forging Process Parameters on Microstructure Evolution of Aluminum Alloy 7050". United States. doi:10.1063/1.2729559.
@article{osti_21057052,
title = {Effects of Forging Process Parameters on Microstructure Evolution of Aluminum Alloy 7050},
author = {Yi Youping and Shi Yan and Yang Jihui and Lin Yongcheng},
abstractNote = {The objective of this work is to investigate the behavior of microstructure evolution of aluminum alloy 7050 under the condition of different forging process parameters by means of combining materials physical model with finite element code. For the purpose of establishing constitutive equation and physical model of microstructure evolution, the isothermal compression test were performed by machine Gleeble 1500 on the condition of temperatures ranging from 250 deg. C to 450 deg. C and constant strain rates of 0.01s-1, 0.1s-1, 1s-1 and 10s-1. The behaviors of microstructure evolutions of aluminum alloy 7050 under difference process parameters were studied by metallographic observations. The experiment results showed that recrystallization during forming process occurred at the critical strain and the volume fraction of recrystallization changed with the temperature and strain rate. According to the results of isothermal compression test, a constitutive equation and an empirical model of DRX were obtained. A finite element code DEFORM 3D was used to analyze the influence of different forging process parameters on the behavior of microstructure evolution in details. The present model and simulation method can be served as a useful tool to predict and control the properties and shape of aluminum alloy 7050 components during forging.},
doi = {10.1063/1.2729559},
journal = {AIP Conference Proceedings},
number = 1,
volume = 907,
place = {United States},
year = {Sat Apr 07 00:00:00 EDT 2007},
month = {Sat Apr 07 00:00:00 EDT 2007}
}
  • Defects such as folding, intercrystalline cracking and flow lines outcrop are very likely to occur in the forging of aluminum alloy. Moreover, it is difficult to achieve the optimal set of process parameters just by trial and error within an industrial environment. In producing 7050 wrought aluminum alloy wheel, a rigid-plastic finite element method (FEM) analysis has been performed to optimize die forging process. Processing parameters were analyzed, focusing on the effects of punch speed, friction factor and temperature. Meanwhile, mechanism as well as the evolution with respect to the defects of the wrought wheel was studied in details. Frommore » an analysis of the results, isothermal die forging was proposed for producing 7050 aluminum alloy wheel with good mechanical properties. Finally, verification experiment was carried out on hydropress.« less
  • The fracture toughness of Al-Zn-Mg-Cu-based 7XXX aluminum alloys decreases with an increase in the extent of recrystallization. In this contribution, the fracture path of plane-strain fracture-toughness specimens of 7050 alloy (a typical alloy of the 7XXX series) is quantitatively characterized as a function of degree of recrystallization, specimen orientation, and aging condition. The fracture path is quantitatively correlated to fracture toughness, and the bulk microstructural attributes estimated via sterological analysis. In the companion article, these quantitative data are used to develop and verify a multiple-fracture micromechanism-based model that relates the fracture toughness to a number of microstructural parameters of themore » partially recrystallized alloy plate.« less
  • A multiple micromechanisms-based model is developed to quantitatively relate the fracture toughness of partially recrystallized 7XXX aluminum alloys to their fracture surface morphology. The model is verified using the experimental data on partially recrystallized 7050 alloy reported in the companion article. It is then used to obtain a quantitative relationship between the fracture toughness and microstructural attributes. The model relates fracture toughness to microstructural parameters such as degree of recrystallization, grain size of recrystallized grains, thickness of recrystallized regions, total surface area of the constituent particles per unit volume, and microstructural anisotropy. The model predicts the changes in the fracturemore » toughness with the specimen orientation.« less
  • Cited by 3
  • The microstructure evolution of the 7050 Al alloy treated by age-forming was studied using a designed device which can simulate the age-forming process. The grain shape, grain boundary misorientation and grain orientation evolution of 7050 Al alloy during age-forming have been quantitatively characterized by electron backscattering diffraction technique. The results show that age-forming produced abundant low-angle boundaries and elongated grains, which attributed to stress induced dislocation movement and grain boundary migration during the age-forming process. On the other side, the stress along rolling direction caused some unstable orientation grains to rotate towards the Brass and S orientations during the age-formingmore » process. Hence, the intensity of the rolling texture orientation in age-formed samples is enhanced. But this effect decays gradually with increasing aging time, since stress decreases and precipitation hardening occurs during the age-forming process. - Highlights: • Quantitative analysis of grain evolution of 7050 Al alloys during age-forming • Stress induces some grain rotation of 7050 Al alloys during age-forming. • Creep leads to elongate grain of 7050 Al alloys during age-forming. • Obtains a trend on texture evolution during age-forming applied stress.« less