Age softening phenomenon and microscopic mechanism of Li−B alloy

锂硼合金的时效软化现象及其微观机制

The age softening phenomenon of the Li−B alloy was investigated by a series of tensile tests under various aging conditions.The results show that the tensile strength of the rolled Li−B alloy decreases with increasing aging time.Higher aging temperature accelerates the softening process,and leads to an early end of aging.A model was proposed to analyze the mechanism of the age softening.The vacancy annihilation is the control factor of age softening.The strength−temperature relationship was estimated by the newly proposed model and a standard heat treatment,annealing at 150℃ for 1 h,was designed to eliminate the age softening of rolled Li−B alloy.

通过不同时效条件下的拉伸试验,研究锂硼合金的时效软化现象。结果表明,随着时效时间的延长,轧制锂硼合金的抗拉强度明显下降;高温可加速此软化过程,使锂硼合金提前进入稳定状态。在此基础上,提出时效软化模型,揭示空位湮灭是时效软化的控制因素。利用该模型得到合金强度−温度的关系,并制定一个标准热处理方法,即在150℃退火1 h,可快速消除锂硼合金的时效软化现象。