scholarly journals Fatigue Cracking Behaviors and Influence Factors of Cast Magnesium Alloys

10.5772/19075 ◽  
2011 ◽  
Author(s):  
Xi-Shu Wang
Keyword(s):  
Magnesium Alloys ◽  
Influence Factors ◽  
Fatigue Cracking ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium

Effects of Distance and Alignment Holes on Fatigue Crack Behaviors of Cast Magnesium Alloys

2008 ◽  
Vol 33-37 ◽  
pp. 13-18 ◽  
Author(s):  
Xi Shu Wang ◽  
Jing Hong Fan ◽  
Bi Sheng Wu ◽  
Ying Li
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Magnesium Alloys ◽  
Fatigue Crack Propagation ◽  
Fatigue Cracking ◽  
Mg17al12 Phase ◽  
Small Cracks ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium ◽  
Small Holes

To study the fatigue microcrack initiation and propagation behaviors of cast magnesium alloys, the small fatigue crack propagation tests were carried out using the in-situ observation with scanning electron microscope (SEM). All initiations and propagations of fatigue small cracks focused on effects of the interaction of artificial two small holes, which there are the different distances and alignments of two small holes. The results indicate that the fatigue small cracks of cast magnesium alloys occurred mainly at the defects or root of notch but the early stage crack propagations were influenced on the distance and alignment between two small holes. For cast AM50 and AM60B alloys, the fatigue small cracking prior to occurred at the weak dendrite boundary and had some concomitances such as the plastic deformation on surface of α-Mg phase. For AZ91 alloy, the fatigue cracking characterization depended mainly on the brittle properties of β-Mg17Al12 phase, which the multi cracks occurred at the boundaries of β-Mg17Al12 phase. The effect of notch on the fatigue cracking behavior becomes weaker when the radius of notch is over 3-4 times than that of average α-Mg grain size. The fatigue crack propagation behaviors varied with the different arrangements of two small holes. The effects of distance and alignment of two small holes on the fatigue crack propagation behaviors are also obvious.

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.

scholarly journals Influence of Multi-Holes on Fatigue Behaviors of Cast Magnesium Alloys Based on In-Situ Scanning Electron Microscope Technology

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1700 ◽  
Author(s):  
Xi-Shu Wang ◽  
Chang-Hao Tan ◽  
Juan Ma ◽  
Xiao-Dong Zhu ◽  
Qing-Yuan Wang
Keyword(s):  
Fatigue Crack ◽  
Electron Microscope ◽  
Crack Initiation ◽  
Scanning Electron Microscope ◽  
Magnesium Alloys ◽  
Mg17al12 Phase ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium ◽  
Scanning Electron

The low cycle fatigue tests on the crack initiation and propagation of cast magnesium alloys with two small holes were carried out by using in-situ scanning electron microscope (SEM) observation technology. The fatigue crack propagation behaviors and fatigue life, which are affected by two small artificial through holes, including the distances between two holes and their locations, were discussed in detail based on the experimental results and the finite element analysis (FEA). The results indicated that the fatigue multi-cracks occurred chiefly at the edges of two holes and the main crack propagation was along the weak dendrite boundary with the plastic deformation vestiges on the surface of α-Mg phase of cast AM50 and AM60B alloys. The fatigue cracking characteristics of cast AZ91 alloy depended mainly on the brittle properties of β-Mg17Al12 phase, in which the multi-cracks occurred still at the edges of two holes and boundaries of β-Mg17Al12 phase. The fatigue crack initiation position of cast magnesium alloys depends strongly on the radius of curvature of through hole or stress concentration factor at the closed edges of two through holes. In addition, the fatigue multi-cracks were amalgamated for the samples with titled 45° of two small holes of cast Mg-Al alloys when the hole distance is less than 4D (D is the diameter of the small hole).

Properties of Fine-Grained Cast Magnesium Alloys for Sheet Manufacture

2013 ◽  
pp. 223-226 ◽  
Author(s):  
Ulrich Draugelates ◽  
Belkacem Bouaifi ◽  
René Poss ◽  
Claus-C. Kedenburg
Keyword(s):  
Magnesium Alloys ◽  
Fine Grained ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium

Shot Peening of Cast Magnesium Alloys

Shot Peening ◽  
2006 ◽  
pp. 374-379 ◽  
Author(s):  
Tomasz Ludian ◽  
Matthias Hilpert ◽  
Armin Kiefer ◽  
Lothar Wagner
Keyword(s):  
Magnesium Alloys ◽  
Shot Peening ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium

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
Keyword(s):  
Aluminum Alloys ◽  
Magnesium Alloys ◽  
Quality Index ◽  
Mechanical Performance ◽  
Cast Aluminum ◽  
Treatment Conditions ◽  
Cast Aluminum Alloys ◽  
Structural Applications ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium

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.

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