摘要
通过电阻率、应力松驰性能和硬度的测定以及差热分析方法，研究了Ｃｕ－Ｎｉ－Ａｌ－Ｔｉ合金的时效特性。结果表明：该合金时效动力学符合Ａｖｒａｍｉ方程，其ｌｎｌｎ１／（１─Ｘ）与ｌｎｔ之间的关系，可用两条不同斜率的直线段来描述，５５０℃时效时两直线交于ｌｎｔ＝６．４处，相应于时效时间１０ｍｉｎ，时效初期相变速率极高，随后逐渐降低；连续加热时，较低温度下形成的富溶质原子区在８００～９００℃区间可能重溶，γ相［Ｎｉ＿３（Ａｌ，Ｔｉ）］在高温下形成，并且可能向热力学更稳定的状态转化；除形成γ相外，还可能形成其它化合物；Ｃｕ－Ｎｉ－Ａｌ－Ｔｉ合金时效稳定性极高，过时效倾向很小。
The aging character of Cu-Ni-Al-Ti alloy has been investigated by measuring resistivity、stress relaxation and hardness and by using DTA method．It is shown that the aging dynam-ics of this alloy is in agreement with the Avrami equation．The relationship between lnln 1／（1－X） and lnt can be described by sections of two lines with different gradients．When lnt≤6．4（aging time t＝10 min），lnln1／（1－X）＝0．7 146 lnt－4．775；when lnt≥6．4， lnln1／（1－t）＝0．2351lnt－1． 60．At early stage of aging the rate of phase transformation is veryhigh and then is slowly decreased．When heared continually the rich solute atoms region isformed at lower temperature and may be resolved in the region of 800～900℃， while γ＇phase［Ni_3（Al，Ti）］ ls formed at higher teniperature and may be translated into more stablestate or other compounds are formed in addition to γ＇phase．Aging stabilily of Cu-Ni-Al-Tialloy is very high and the overage tendency is very small．
基金
湖南省科委重点攻关资助项目
关键词
铜合金
时效
相变
Cu－alloy；aging；phase transformation
