ひずみ範囲分割法によるはんだの疲労寿命評価法

抄録

Torsional fatigue tests were performed on 60Sn-40Pb solder under strain control, and a method for the solder fatigue life prediction was investigated. The type of specimen was a thin-walled cylinder. Two cycling frequencies of 0.001 Hz and 0.01 Hz were used at 303 K. Using the test data at 0.03-1.0 Hz shown in the previous paper, as well as the present test data, the following results were obtained. ( 1 )The fatigue life and the plastic shearing strain range, which was found by a partition of the inelastic shearing strain range, could be correlated by the Coffin-Manson law for each cycling frequency. ( 2 )A life prediction formula was obtained on the basis of the strain-range partitioning approach and the linear cumulative damage rule for the superposition of both plastic and creep deformations. The values calculated by the formula nearly coincided with the test results.