A constitutive model for predicting flow stress of Al18B4O33w/AZ91D composite during hot compression and its validation

• Published in: Computational materials science Vol. 50; no. 8; pp. 2422 - 2426
• Main Authors: Wang, Zhenjun, Qi, Lehua, Zhou, Jiming, Guan, Juntao, Liu, Jian
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 01-06-2011
• Subjects: Applied sciences; Computer simulation; Constitutive relationships; Elasticity. Plasticity; Exact sciences and technology; Fibre reinforced metals; Finite element method; Flow stress; Hot pressing; Magnesium; Mathematical models; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Powder metallurgy. Composite materials; Production techniques; Yield strength; Hot deformation; Constitutive equation; Short fiber; B; Plastic flow; Fibre reinforced metal; Non linear regression; FE simulation; Metal matrix composite; Constitutive model; Aluminium Borates; Al; AZ91 D; Compression test; Composite material; O; Finite element method; Magnesium base alloys; Hot compression; Flow stress; Strain rate
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2011.03.020

The flow stress properties of 25vol.% aluminum borate whiskers reinforced magnesium composite fabricated by gas pressure infiltration were obtained by hot compression test. According to the experimental results, a modified constitutive model was proposed and applied to description of the relationship between deformation temperature, strain, strain rate and flow stress. Based on the experimental data, the material constants of the model were identified by application of nonlinear regression method. Additionally, the derived constitutive model was embedded in a FEM software, by which the experimental hot compression process was simulated. The results shown the load-stroke values of hot compression calculated by FE simulations are in agreement with the measured results in experiments, which indicate the developed constitutive equation can provide an accurate and sound description of plastic deformation of the composite during hot forming process.