Scanning Electron Fractographic Study of Aluminum Oxide as a Function of Testing Temperature and Grain Size
Polycrystalline Lucalox of 5, 20, and 30 µ grain size was fractured at room temperature, 400°, 700°, and 1000°C. Extensive cleavage and intercrystalline fracture was observed using the scanning electron microscope. The extent of cleavage decreased with increase in temperature and grain size. These results are explained in terms of temperature dependence of fracture stress for cleavage and grain boundary fracture, stress concentration at sharp-edge pores, and favorable orientations of some grains relative to the loading axis for cleavage.
KeywordsSurface Marking Cleavage Plane Stress Raiser Fracture Face Fine Cleavage
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