Mechanical properties and failure characteristics of cast and extruded Mg97Y2Zn1 alloys with LPSO phase
| Autor: | Shuhei Takeuchi, Masafumi Matsushita, Mitsuhiro Okayasu, Naoya Tada, Michiaki Yamasaki, Yoshihito Kawamura |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science Mechanical Engineering Metallurgy technology industry and agriculture 02 engineering and technology Paris' law equipment and supplies 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences Fatigue limit Crack closure Mechanics of Materials Casting (metalworking) 0103 physical sciences Ultimate tensile strength General Materials Science Deformation (engineering) Magnesium alloy 0210 nano-technology |
| Zdroj: | Materials Science and Engineering: A. 652:14-29 |
| ISSN: | 0921-5093 |
| Popis: | Mechanical properties and failure characteristics of Mg97Y2Zn1 (at%) alloys, prepared by gravity casting and extrusion processes, are examined experimentally. High tensile and fatigue strengths are obtained for extruded Mg97Y2Zn1 alloys, with the values being approximately twice as high as those for cast Mg97Y2Zn1 alloys. Such high strengths are attributed to the high internal stress arising from the complicated microstructure and severe lattice strain in the α-Mg and long-period stacking order phases. On the other hand, a high fracture strain is obtained for cast Mg97Y2Zn1 alloy, which is affected not only by the lower internal stress, but also severe kink deformation. The failure characteristics, e.g., crack growth characteristics are examined via direct observation during tensile and fatigue tests at micro- and nano-scales. Meandering fatigue crack growth is obtained for the cast Mg97Y2Zn1 alloys. The mean roughness of the fracture surface for cast Mg97Y2Zn1 alloys is more than twice as high as that for commercially available AM60 and AZ91 cast alloys. A coarse fracture surface that was observed in the cast Mg97Y2Zn1 alloys would make severe roughness-induced crack closure, leading to high fatigue strength. |
| Databáze: | OpenAIRE |
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