注入氦不锈钢中氦泡热形核及长大研究

THERMAL NUCLEATION AND GROWTH OF He BUBBLES IN He IMPLANTED STAINLESS STEELS

本文利用透射电镜观察了HR-2及SS321不锈钢注入He^+并在T<1023K不同温度退火后的He泡结构,发现T=0.45T_m是一个转变点,当0.3T_m<T<0.45T_m时,主要是He泡继续形核过程;T>0.45T_m时,He泡主要通过迁移和合并而长大,长大激活能的实验值分别为0.41eV和0.31eV,实验结果表明,HR-2钢中He泡数密度在整个测量温区内均大于SS321钢,并且材料迅速肿胀的开始温度也高于SS321钢。

Nucleation and growth of He bubbles at different annealing temperatures T≤1023 K in stainless steels HR-2 and SS321, implanted with He^+ (40—70 keV, 1×10^(16)-6×10^(17) He^+ /cm^2), were observed under TEM. T=0.45T_m seems to be a transition temperature. The He bubbles continue mainly their nucleation at 0.3T_m<T<0.45T_m, and grow predominantly at T≥0.45T_m, due probably to migration and coalescence by surface diffusion of metal atoms around the bubbles. The apparent activation energies for the growth are found to be 0.41 and 0.31 eV for HR-2 and SS321 respectively. The bubble density in HR-2 is greater than that in SS321 within whole measuring temperature range, and the onset temperature of rapid swelling is also higher. It is believed that the resistance of HR-2 to He is superior to that of SS321.