Mechanical Performance Evaluation of Cast Magnesium Alloys for Automotive and Aeronautical Applications

2006 ◽  
Vol 129 (3) ◽  
pp. 422-430 ◽  
Author(s):  
Sp. G. Pantelakis ◽  
N. D. Alexopoulos ◽  
A. N. Chamos

The potential of cast magnesium alloys for being used as structural materials in lightweight applications is assessed. The ability of the alloys for mechanical performance is evaluated and compared against the ability of widely used structural aircraft cast aluminum alloys. The specific quality index QDS, devised for evaluating both cast and wrought aluminum alloys, will be exploited to evaluate the ability of a number of cast magnesium alloys for mechanical performance. The exploited quality index QDS involves the material’s yield strength Rp to account for strength, the strain energy density W to account for both tensile ductility and toughness, and the material’s density ρ. The effects of differences in chemical composition and heat treatment conditions on the mechanical performance of cast magnesium alloys have been assessed. The use of the quality index QDS has been proved to appreciably facilitate the evaluation of the mechanical performance of cast magnesium alloys and also the comparison between alloys of different base materials. The results quantify the gap to be closed such as to involve cast magnesium alloys in aircraft structural applications.

2014 ◽  
Vol 794-796 ◽  
pp. 489-494 ◽  
Author(s):  
J.H. Sandoval ◽  
Adel M.A. Mohamed ◽  
S. Valtierra ◽  
F.H. Samuel

Cast aluminum alloys are an important group of materials which find wide application in the automotive industry. Insufficient studies have been carried out to date with regard to the mechanical performance of the aged A354 alloy. Therefore, the present work investigates the Quality index charts with the purpose of setting the limits of the tensile properties, as well as for comparing the mechanical behavior of cast alloy A354, to delineate the effect of the solution treatment applied. Tensile properties upon artificial aging in the temperature range of 155–350oC for times ranging from 2 to 100 hours are also investigated. The results showed that the use of quality index charts is a satisfactory method for presenting tensile test results and, for assessing the effect of solution and aging treatment conditions subjected to the modified and grain-refined A354 alloys. It is also observed that the quality index, Q, is more sensitive to variations in the tensile ductility than to tensile strength.


2017 ◽  
Vol 62 (4) ◽  
pp. 2365-2370 ◽  
Author(s):  
L. Cizek ◽  
S. Rusz ◽  
O. Hilser ◽  
R. Śliwa ◽  
D. Kuc ◽  
...  

AbstractA growing interest in wrought magnesium alloys has been noticed recently, mainly due to development of various SPD (severe plastic deformation) methods that enable significant refinement of the microstructure and – as a result – improvement of various functional properties of products. However, forming as-cast magnesium alloys with the increased aluminum content at room temperature is almost impossible. Therefore, application of heat treatment before forming or forming at elevated temperature is recommended for these alloys. The paper presents the influence of selected heat treatment conditions on the microstructure and the mechanical properties of the as-cast AZ91 alloy. Deformation behaviour of the as-cast AZ61 alloy at elevated temperatures was analysed as well. The microstructure analysis was performed by means of both light microscopy and SEM. The latter one was used also for fracture analysis. Moreover, the effect of chemical composition modification by lithium addition on the microstructure of the AZ31-based alloy is presented. The test results can be helpful in preparation of the magnesium-aluminum alloys for further processing by means of SPD methods.


Author(s):  
Murat Tiryakioğlu ◽  
Nelson Netto

Microstructural and mechanical data from the literature of friction stir processed (FSPed) cast aluminum alloys were reanalyzed. Results indicated that friction stir processing (FSP) produced more homogeneous microstructures, with finer eutectic Si particles, grains, and intermetallics. However, a relationship between microstructural measures and process parameters could not be established. Regardless of the resultant microstructure, structural casting defects, i.e., pores and oxide films, were reduced in size or completely eliminated after FSP. Consequently, ductility and fatigue life were drastically improved by FSP. Quality index analysis showed that some FSPed specimens have a higher structural quality than aerospace and premium quality castings, and can be used to determine the intrinsic properties of cast aluminum alloys.


2007 ◽  
Vol 561-565 ◽  
pp. 163-166
Author(s):  
Yoshihiro Terada ◽  
Tatsuo Sato

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.


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