CAJ | 학술논문

用正电子湮没寿命方法和超声衰减方法对金属铝合金和钢疲劳样品进行了测量。结果表明，在疲劳加载次数较小时，正电子参数将随着疲劳加载次数的增加而增加；但当疲劳加载次数足够大时，金属样品内部发生了结构的变化，如空位之间发生合并而形成空位团，位错之间发生合并、缠绕，这些结构的变化导致正电子平均寿命在到达最大值后下降。在用超声方法对金属疲劳样品进行测量时，观察到衰减常数有类似的变化趋势。
용정전자인몰수명방법화초성쇠감방법대금속려합금화강피로양품진행료측량。결과표명，재피로가재차수교소시，정전자삼수장수착피로가재차수적증가이증가；단당피로가재차수족구대시，금속양품내부발생료결구적변화，여공위지간발생합병이형성공위단，위착지간발생합병、전요，저사결구적변화도치정전자평균수명재도체최대치후하강。재용초성방법대금속피로양품진행측량시，관찰도쇠감상수유유사적변화추세。
The fatigue of aluminum and steel samples was studied by using positron annihilation technique(PAT) and ultrasonic decay method, respectively. When the number of fatigue cycle is small, some of positron parameters increase with the increment of fatigue cycles because of theextreme sensitivity of positron to very small vacancies. But some structural transformation might happen when the number of fatigue cycle is large enough. For example some vacancies might aggregate and form vacancy clusters. Some dislocations might annex or tangle. These kinds of transformationin structure will reduce the density of vacancies and dislocations, whichis responsible for the decreasing trend of the curve after the average lifetime of positron achieves its maximum. The result of ultrasonic decay constant measurement also shows similar trend.