The improved arrhenius model with variable parameters of flow behavior characterizing for the as-cast AZ80 magnesium alloy

Abstract

In order to study the hot working behaviour of as-cast AZ80 magnesium alloy, a series of isothermal upsetting tests with height reduction of 60% were performed at the temperature range of 523-673 K and the strain rate range of 0.01-10 s -1 on a servo-hydraulic Gleeble-1500 machine simulator. Based on the regression analysis for Arrhenius type equation of flow stress, the activation energy of deformation was determined to be Q = 168.6606 KJ·mol -1 , and material constants A, n and α in the equation also were calculated respectively to predict the peak stress during hot deformation. A 7 th order polynomial was used to represent the influence of strain on these parameters (i.e Q, lnA, n and α). The Arrhenius equation was further developed by taking account of the effect of strain on the flow stress to describe the flow behavior during the whole experimental temperature and strain rate range. Then comparison between the predicted results and test results shows that the correlation coefficient and average absolute relative error is 0.99 and 6.63%, respectively. The flow stress predicted by developed equation can give an accurate and precise description of the flow behaviour for AZ80 magnesium alloy.

Hot tensile deformation behaviors and constitutive model of an Al–Zn–Mg–Cu alloy

“…Also, some similar http://dx.doi.org/10.1016/j.matdes.2014.02.052 0261-3069/Ó 2014 Elsevier Ltd. All rights reserved. constitutive equations were established for the novel bimetal consisting of pearlitic steel and low carbon steel [35], AISI 420 stainless steel [36], GCr15 steel [37], Sanicro-28 super-austenitic stainless steel [38], Ni-42.5Ti-3Cu alloy [39], as-cast Ti-43Al-4Nb-1.4W-0.6B alloy [40], Al-3Cu-0.5Sc alloy [41], spray-deposited Al-Zn-Mg-Cu alloy [42], as-cast AZ80 magnesium alloy [43], cast A356 aluminum alloy [44], 42CrMo steel [45], near-a titanium alloy IMI834 [46], and pure titanium [47]. Additionally, based on the combination of the Arrhenius-type model and Hensel-Spittel Hensel-Spittel equation, Spigarelli and El Mehtedi [48] developed a new constitutive model to describe the plastic flow behavior of AA6005 aluminum alloy tested in torsion.…”

Modelling the Hot Flow Behaviors of AZ80 Alloy by BP-ANN and the Applications in Accuracy Improvement of Computations

“…Lin et al 21 and Quan et al 22 revised the strain-dependent hyperbolic sine constitutive models by incorporating the hot forming parameters (such as material constants n and a, and structure factor A, activation energy of deformation Q). Other kinds of phenomenological constitutive models include Khan-Huang-Liang (KHL), and Johnson-Cook (JC) etc., showing large differences of accuracy in different range of temperatures and strain rates 16,23,24 .…”

“…Lin et al 45,46 presented a modified hyperbolic sine constitutive equation, in which the hot forming parameters (such as Q, n, a, and A) as functions of strain were incorporated in the improved the Arrhenius-type constitutive equation. Quan et al 22 calculated a series of coefficients (Q, n, A, and a) shown in Table 2 …”

Numerical Description of Hot Flow Behaviors at Ti-6Al-2Zr-1Mo-1V Alloy By GA-SVR and Relative Applications

“…Recently, the Arrhenius-type equation and their revised forms of phenomenological models were utilized to model the hot flow behaviors of many materials, such as Ti-6Al-4V 15 ,Ti60 16 , and pure titanium 17 , etc. Lin et al 18,19 and Quan et al 20 improved the initial Arrhenius-type equations by incorporating strain and some material parameters (such as structure factor A and activation energy of deformation Q) to obtain more accurate Arrhenius-type equation. Other phenomenological constitutive models involve the typical Johnson-Cook (JC) model and Khan-Huang-Liang (KHL) model etc., however, they exhibit large accuracy deviations at different strain rates and temperatures [21][22][23][24] .…”