Static Fatigue Behavior of Alumina Ceramic Joint.

Abstract

A study was made to investigate the static fatigue behavior with alumina-alumina and alumina-stainless steel butt joints. The static fatigue test was performed under a constant bending moment at constant temperatures ranging from 580 to 888 K. For the specimen bonded at 903 K, static fatigue life, tf, is related to the applied stress o and test temperature T, regardless of the adherent materials, as follows ; 1/tf =(1/t0)(1/σ)m0 exp {-(Q0-αln σ)/RT}, where t0, m0 and α are material constant, R the gas constant and Q0 is activation energy of the fatigue process. While for the specimen bonded at higher temperature of 1073 K, tf is expressed as following form ; 1/tf =(1/t, 0)σm exp {-Q/RT}, where t, 0 and m are material constant. A good agreement between the calculated and the observed value of fatigue life of the joint is obtained. The SEM observation of the fracture surface was also made and a possible mechanism for static fatigue process in the bonded zone was discussed.