Zn-22wt％Al合金是一种共析成分合金。将一组此合金样品在370℃保温3小时,然后淬火于冰盐水中,这样就形成了具有微细等轴晶粒的组织。再将这组样品在250℃保温不同时间,可得到晶粒尺寸在0.3μm至1.2μm范围内的一系列样品。本工作利用正电子湮没技术对样品进行了测量。寿命谱两寿命解谱结果表明,对于不同晶粒尺寸的样品,第二寿命τ_2都是在240ps左右,这个寿命值对应于晶界的捕获寿命,类似于正电子在空位或位错中的寿命, Zn-22wt% Al alloy is an eutectoid alloy. A set of this alloy sample was incubated at 370 ° C for 3 hours and then quenched in ice-salt water to form a microstructure having fine equiaxed grains. The samples were then incubated at 250 ° C for different times to obtain a series of samples with grain sizes in the range of 0.3μm to 1.2μm. In this work, positron annihilation was used to measure the samples. The results of life spectrum spectra of two lifetimes show that for the samples with different grain sizes, the second lifetime τ_2 is about 240ps, which corresponds to the capture lifetime of the grain boundary, similar to the lifetime of positrons in vacancies or dislocations ,