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研究了Cu-Zn-Al合金分别经水淬、分级淬火和淬火加时效处理后,马氏体的有序化程度及其和形状记忆效应(SME)之间的关系.有序化程度用一些特定马氏体线对的面间距差值△d来表征,线对指数应满足下式:(h_1~2-h_2~2)/3=(k_2~2-k_1~2)/n(对9R马氏体n=1,对18R马氏体N=4).分级淬火得到M18R马氏体,其△d值随分级等温时间而增大,与形状恢复能力η的提高一致.水淬得到M9R马氏体,刚淬火状态有相当大的△d和良好的SME,但室温停留使△d和η均下降,TEM点阵条纹象证实这是淬火过饱和空位在(001)_M基面聚集、降低有序程度的结果.淬火后高温时效(180℃)或过高的分级温度都会使△d和η下降,这与α相析出以及可能发生的溶质原子偏聚有关,都会降低有序程度.
The relationship between martensite ordering degree and shape memory effect (SME) of Cu-Zn-Al alloy after water quenching, fractional quenching, quenching and aging treatment were studied respectively. The difference of the interplanar spacings of specific martensite pairs is characterized by the line pair index which should satisfy the following formula: (h_1 ~ 2 ~ h_2 ~ 2) / 3 = (k_2 ~ 2 ~ k_1 ~ 2) / n Martensite n = 1, 18R martensite N = 4) .The M18R martensite was obtained by fractional quenching, and its △ d value increased with the grading isothermal time, which was consistent with the increase of the shape recovery ability η. Martensite, just quenched state has a relatively large △ d and good SME, but at room temperature so that Δd and η decreased, TEM lattice streaks confirmed this is quenched supersaturated vacancies in the (001) _M base surface aggregation, Decreasing the degree of order of the results of high temperature aging after quenching (180 ℃) or too high classification temperature will make △ d and η down, which α precipitation and the possible segregation of solute atoms will reduce the degree of order.