ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
To study the fatigue microcrack initiation and propagation behaviors of castmagnesium alloys, the small fatigue crack propagation tests were carried out using the in-situobservation with scanning electron microscope (SEM). All initiations and propagations of fatiguesmall cracks focused on effects of the interaction of artificial two small holes, which there are thedifferent distances and alignments of two small holes. The results indicate that the fatigue smallcracks of cast magnesium alloys occurred mainly at the defects or root of notch but the early stagecrack propagations were influenced on the distance and alignment between two small holes. For castAM50 and AM60B alloys, the fatigue small cracking prior to occurred at the weak dendrite boundaryand had some concomitances such as the plastic deformation on surface of α-Mg phase. For AZ91alloy, the fatigue cracking characterization depended mainly on the brittle properties of β-Mg17Al12phase, which the multi cracks occurred at the boundaries of β-Mg17Al12 phase. The effect of notch onthe fatigue cracking behavior becomes weaker when the radius of notch is over 3-4 times than that ofaverage α-Mg grain size. The fatigue crack propagation behaviors varied with the differentarrangements of two small holes. The effects of distance and alignment of two small holes on thefatigue crack propagation behaviors are also obvious
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.33-37.13.pdf
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