On the High Formability of AZ31-0.5Ca Magnesium Alloy

Abstract

In this work, we investigated the effect of Ca on the formability of the AZ31 Mg alloy. For this purpose, the microstructure, texture, mechanical properties and formability of AZ31 Mg alloy samples containing 0.5 wt. % Ca (AZ31-0.5Ca) were studied. For comparison, the performance of Ca-Free AZ31 alloy samples with similar grain size was also investigated. In addition, formability of this alloy was reached at a high punch speed. The results of this work showed that the addition of 0.5 wt. % Ca can enhance the formability of the AZ31 alloy, which was three times greater than that of the Ca-Free AZ31 alloy. The improved formability was attributed to the formation of (Mg,Al)2Ca particles (~1 μm), which, in turn, contribute to reducing the intensity of the strong basal texture during the primary processing of the alloy. The in-grain misorientation axis analysis determined by electron back-scattered diffraction and critical resolved shear stress calculations carried out by the viscoplastic self-consistent model showed that the non-basal slip systems could be activated in the AZ31-0.5Ca alloy.

High Performance Fine-Grained Biodegradable Mg-Zn-Ca Alloys Processed by Severe Plastic Deformation

“…A great deal of work has been dedicated to developing a technological procedure capable of weakening the basal texture and/or reducing the critical resolved shear stresses (CRSS) of the non-basal slip systems. Among those, specific alloying, primarily with Rare Earth elements [80] (with regard to the present work, it should be noticed that the addition of calcium into the Mg-Zn system also weakens the strong basal textures and promotes grain refinement during hot-extrusion of Mg-Zn-Ca and Mg-Zn-Al-Ca alloys due to the particle stimulated nucleation of dynamic recrystallization [81,82]), and imposing shear deformation, e.g., via asymmetrical rolling [83] or ECAP [75,[84][85][86] have gained the greatest popularity. Agnew et al [87,88] have shown that the texture becomes stronger with the increasing number of ECAP-Bc passes.…”

Microstructure and Hot Deformation Behavior of Twin Roll Cast Mg-2Zn-1Al-0.3Ca Alloy

“…The XRD results of the TRC condition imply the occurrence of Mg 2 Ca precipitates, which can act as nucleation sites for recrystallization. The addition of calcium contributes to the formation of the Mg 2 Ca phase [35,36]. XRD results reveal, that precipitates have dissolved during heat treatment at 460 °C, because only α-magnesium matrix was detected.…”

Mg-Alloys for Forging Applications—A Review

“…The addition of Ca to Mg-Al-alloys leads to various beneficial effects for wrought alloys, for example, reduced anisotropy [101,102], reduced grain size [103], increased creep resistance [104,105] and the ability of precipitation hardening by Mg 2 Ca and Al 2 Ca intermetallic phases [8]. Additionally, the oxidation tendency of Mg is reduced when Ca is present in the alloy [106][107][108], reducing possible fire hazards during alloy preparation, melt handling and high temperature processing (e.g., heat treatment, forging, ...).…”