scholarly journals Anelastic Behaviour of Commercial Die-Cast Magnesium Alloys: Effect of Temperature and Alloy Composition

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7220
Author(s):  
Hua Qian Ang
Keyword(s):  
Magnesium Alloys ◽  
Effect Of Temperature ◽  
Anelastic Strain ◽  
Solid Solution Softening ◽  
Die Cast ◽  
Slip Planes ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium ◽  
Increasing Temperature ◽  
Anelastic Deformation

The anelastic deformation, resulting from partial reversal of {101¯2} twinning, is studied at room temperature to 150 °C on several commercial die-cast magnesium alloys for the first time. The magnitude of anelastic strain decreases with increasing temperature. For inter-alloy comparison, AZ91 shows the largest maximum anelastic strain, while AM40 and AM60 show similar maximum anelastic strain. The phenomenon is discussed in terms of solid solution softening and hardening of slip planes and how they influence twinning. T5-aged AE44 consistently shows smaller magnitude of anelasticity compared to as-cast AE44, suggesting that the precipitates formed during ageing may decrease the twin-boundary mobility and further suppress untwinning. Presence of anelasticity poses a challenge to yield strength measurement using the conventional 0.2% offset method, and a more accurate and consistent method of using a higher offset strain or a lower modulus is proposed in this study.

Long Term Creep Properties of a Die-Cast Mg-Al-Ca Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 163-166
Author(s):  
Yoshihiro Terada ◽  
Tatsuo Sato
Keyword(s):  
Creep Rate ◽  
Magnesium Alloys ◽  
Cast Alloy ◽  
Rupture Life ◽  
Testing Temperature ◽  
Creep Rupture ◽  
Die Cast ◽  
Cast Magnesium Alloys ◽  
Term Creep ◽  
Cast Magnesium

Creep rupture tests were performed for a die-cast Mg-Al-Ca alloy AX52 (X representing calcium) at 29 kinds of creep conditions in the temperature range between 423 and 498 K. The creep curve for the alloy is characterized by a minimum in the creep rate followed by an accelerating stage. The minimum creep rate (ε& m) and the creep rupture life (trup) follow the phenomenological Monkman-Grant relationship; trup = C0 /ε& m m. It is found for the AX52 die-cast alloy that the exponent m is unity and the constant C0 is 2.0 x 10-2, independent of creep testing temperature. The values of m and C0 are compared with those for another die-cast magnesium alloys. The value m=1 is generally detected for die-cast magnesium alloys. On the contrary, the value of C0 sensitively depends on alloy composition, which is reduced with increasing the concentration of alloying elements such as Al, Zn and Ca.

Optimisation of the Quality of High Pressure Die Cast Magnesium Alloys

2013 ◽  
pp. 305-313
Author(s):  
A.K. Dahle ◽  
S. Saunes ◽  
D.H. StJohn ◽  
H. Westengen
Keyword(s):  
High Pressure ◽  
Magnesium Alloys ◽  
Die Cast ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium

scholarly journals Proof stress measurement of die-cast magnesium alloys

2016 ◽  
Vol 112 ◽  
pp. 402-409 ◽  
Author(s):  
Hua Qian Ang ◽  
Trevor B. Abbott ◽  
Suming Zhu ◽  
Chengfan Gu ◽  
Mark A. Easton
Keyword(s):  
Magnesium Alloys ◽  
Stress Measurement ◽  
Proof Stress ◽  
Die Cast ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium

Predicting the flow stress of high pressure die cast magnesium alloys

2014 ◽  
Vol 605 ◽  
pp. 237-243 ◽  
Author(s):  
P. Sharifi ◽  
Y. Fan ◽  
J.P. Weiler ◽  
J.T. Wood
Keyword(s):  
High Pressure ◽  
Flow Stress ◽  
Magnesium Alloys ◽  
Die Cast ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium

Process-Structure-Property Relationships for Magnesium Alloys

2012 ◽  
Vol 706-709 ◽  
pp. 1273-1278 ◽  
Author(s):  
Jonathan P. Weiler ◽  
J.T. Wood ◽  
I. Basu
Keyword(s):  
Magnesium Alloys ◽  
Area Fraction ◽  
Structure Property ◽  
Maximum Area ◽  
X Ray ◽  
Structure Property Relationships ◽  
Die Cast ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium ◽  
Process Structure

Gravity step-casting experiments were performed to investigate process-structure-property relationships in three different die-cast magnesium alloys – AM60, AZ91 and AE44. The step-cast mold was instrumented to capture temperature profiles of the solidification of molten magnesium. This paper investigates the structure-property relationships of these magnesium alloys, specifically the dependence of the fracture properties upon the porosity that forms during the casting process. Sixteen tensile specimens were cut from the step-casting perpendicular to the solidification front, for each alloy examined. Correlations from X-ray tomography data were used to estimate the maximum area fraction of porosity from the average volumetric porosity in the specimens, assuming a typical size and spatial distribution of porosity. This relationship can be used in the absence of more accurate measure of porosity (i.e. serial sectioning, computed x-ray tomography). A failure model for die-cast alloys – which depends upon the strain-hardening coefficient and the maximum area fraction of porosity in the specimen – was used to predict fracture strains for each specimen. The experimental tensile elongation of each specimen was compared with predicted values. The resulting mechanical properties determined from these cast magnesium alloys will be used to develop process-structure-property relationships.

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