不同成分Ti-Ni合金的正电子湮没研究

用正电子湮没Doppler展宽能谱测量了不同成分近等原子Ti-Ni合金的不同温度淬火和1000℃淬火叉经不同温度退火后试样的线形S参数,结果表明:(1)淬火曲线高温部分和退火曲线低温部分的S参数变化符合单空位机制;(2)正电子可探测到沉淀相的温度区间为:Ti-49.0at% Ni约是300°~700℃,Ti-50.0at% Ni约是350°~700℃,Ti-50.5at% Ni、Ti-51.0at% Ni和Ti-51.5at% Ni均约是400°~700℃;(3)富Ni侧合金中的"缺陷"量易受处理条件影响;(4)在相似的处理条件下,富Ni侧合金的"缺陷"量比富Ti侧的低.

A POSITRON ANNIHILATION STUDY FOR THE Ti-Ni ALLOYS

The measurements of the S-shaped parameter of Doppler-broadening of positron annihilation were carried out for the near-equiatomic Ti-Ni alloys of different concentrations subjected to quenching at different temperatures and then annealed at different temperatures after quenching at 1000℃. The. result showed:(1) the change of S-parameter in the high temperature range of the quenching curves and in the low temperature range of the annealing curves could be explained by the mechanism of single vacancy, (2) for the Ti-Ni alloys, the positron could detect the precipitation in these probable ranges of temperature:300°~700℃ in Ti-49.0 at% Ni,350°~700℃ in Ti-50.0 at%Ni, and 400°~700℃ in Ti-50.5at% Ni, Ti-51.0at% Ni and Ti-51.5 at% Ni, (3) the amount of "defects" on the Ni-rich side was changed more easily by the conditions of the treatment than that on the Ti-rich side, and (4) the amount of "defects" on the Ni-rich side was lower than that on the Ti-rich side under the same condition of heat-treatment.