Alumina Ceramic Fatigue Resistance

The dominant mechanism of fatigue of the alumina ceramic of this study at temperatures ranging from 25 c to 216 c appeared to be a thermally activated corrosion reaction with water vapor.

Alumina ceramic fatigue resistance. Ceramic s exceptional properties in the areas of mechanical strength and extreme hardness make these a versatfie class of materials. Failure over time does occur in brittle materials however despite the absence ö the crack tip plasticity that is the hallmark of materials known to exhibit fatigue. 614 16 wright air development center air research and development command. The cyclic fatigue as well as the interaction between the two using pressable fluorapatite.

Blatberwiek university of minnesota september 1953 g materials laboratory contract no. Sarkar 1994 studied the fatigue behaviors of fine grained alumina under repeated impact loading and found that the fatigue resistance parameter is 17 12 while the endurance limit is around 270mpa which is about 38 of the single impact strength of the material and also found that fatigue cracks are trans granular near. It is particularly shown that the glass bonded alumina ceramics are considerably less fatigue resistant than high purity alumina ceramics. Af 33 038 20840 rdo no.

The fatigue behavior of a polycrystalline alumina was investigated. Our fatigue study has shown that graded gag exhibited much better resistance to long term flexural fracture compared with homogeneous alumina. Fatigue properties of aluminum alloys at various direct stress ratios part 1. The apparent activation energy for fatigue of this material is 8 8 kcal mole for static loading and 6 3 kcal mole for cyclic loading.

Mantyla corrosion resistance of porous alumina ceramics. Stress conditions consisted of a static tensile stress and a static tensile stress with superposed sinusoidal cyclic stress. Composite beam theory predicts that the low modulus surface in graded gag is able to effectively dissipate the maximum flexural stress and redistribute it to the bulk of the material away from the. Ceramics for fatigue resistance it is not altogether clear that conventional fatigue actually takes place in ceramic materials.

In combination with other properties such as dimensional stability and temperature and corrosion resistance both traditional and advanced ceramics can be used in a wide range of wear resistant applications.