アルミナジルコニアセラミックスの曲げ疲労(<特集>疲労特集)

概要

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Bending fatigue experiments were carried out for Al_2O_3-ZrO_2 and Al_2O_3 ceramics under a pulsation of trapezoidal loading at 288 and 873K. In order to evaluate the fatigue damage, the degree of phase transformation of dispersed ZrO_2 from the tetragonal to monoclinic phase was studied by means of X-ray analysis, and the crack length at Vicker's indentation was measured. The results obtained were summerized as follows; (1) The fatigue life was comparatively short but a clear fatigue limit could be seen at both temperatures for Al_2O_3-ZrO_2, although such a fatigue limit could not be seen for Al_2O_3. From these results , it is considered that fatigue fracture originates at microcracks around the dispersed ZrO_2. (2) The crack length formed at a Vicker's indentation on the tensile side of each specimen surface after the repeated pulsation of loading was much longer in the logitudinal direction than in the transverse direction. (3) No increase in the phase transformation of dispersed ZrO_2due to the pulsation of loading was observed at both 288 and 873K. (4) In order to explain the difference in indentation crack length, a simple model was proposed.
社団法人日本材料学会の論文
1987-10-15