Alumina Ceramic Fatigue Resistance

Alumina ceramic has excellent thermal stability which means that it is widely used in areas where resistance to high temperatures is essential.

Alumina ceramic fatigue resistance.

High purity alumina ceramics are ideal for environments where resistance to wear and corrosive substances are required. Tantalum ions with the average energy about 145 kev were used in experiments. These predictions are in agreement. Ceramic research and development is to produce tough strong ceramics that perform reliably.

Alumina ceramic is the material of choice for alumina wear parts. Consistently shorter failure times were seen in the cyclic mode. Estimation of the sheet resistance was performed from analysis of volt ampere characteristics by measuring the leakage current. 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.

Our fatigue study has shown that graded gag exhibited much better resistance to long term flexural fracture compared with homogeneous alumina. The thickness of alumina ceramics can withstand over 8000v voltage per millimeter. Alumina ceramics are high temperature resistant and can be used for a long time at 1600 degrees. Alumina ceramic has strong corrosion resistance.

In this study time to failure from a steady stress was compared to a tension compression fatigue test at equivalent peak 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 strength limiting surface flaws zhang and ma 2009. Fatigue is predicted to have a very high b a modest c a higher fatigue resistance for tougher ceramics and a stronger kmax dependence for less tough ceramics. High temperature ability alumina can be used in both oxidizing and reducing atmospheres up to 1650 c 2900 f and in vacuum environments up to 2000 c 3600 f.

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. The results of investigation of the sheet resistance of alumina ceramic as a function of the fluence of implanted metal ions are presented. Fracture toughness values are used extensively to characterize the fracture resistance of ceramics and brittle materials. Abrasion resistant alumina is a very hard ceramic and is excellent at resisting abrasion.

Tests on disk specimens with indentation cracks reveal no failures below the static fatigue limit. The behavior under cyclic tension tension loading of an alumina ceramic with pronounced crack bridging r curve characteristics is studied.