退火条件对6016铝合金硬度和蠕变性能的影响

Effects of Different Annealing Conditions on the Hardness and Creep Behavior of 6016 Aluminum Alloys

关键词:  6016铝合金  热处理  时效  硬度  蠕变系数

Key words:  6016 aluminum alloy  heat treatment  aging  hardness  creep coefficient

摘要:

[目的]研究6016铝合金在不同退火温度和时效条件下的硬度和蠕变性能,为生产应用领域提供参考依据。[方法]利用纳米压痕技术对不同退火温度和时效处理的6016铝合金的硬度及蠕变性能进行测试。[结果]退火温度对6016铝合金的硬度影响不大;随着自然时效时间的延长,各试样的硬度值都出现先略微变化,然后大幅减小再增大的趋势。蠕变系数在不同自然时效时间下出现浮动现象,蠕变系数n=1.723~2.796,各试样蠕变系数呈现先变小后增大再减小的趋势,在7 d时效时出现最优值,在27 d时出现峰值,随时间延长蠕变系数出现回归现象,材料形变速率减小,并趋于一个相对稳定状态;但在同样时效条件下它们的差异并不明显。[结论]经过不同温度和不同时效时间处理的6016铝合金,其硬度随时效时间变化而变化。热处理对蠕变系数的影响较弱,6016铝合金的力学性能比较稳定。对6016铝合金板材采用"退火处理+自然时效"后,最适宜的应用时间是在两个月后。

Abstract:

[Objective] The hardness and creep behavior of 6016 aluminum alloys with different annealing and aging conditions were studied, which could provide a reference for production and application field.[Methods] The nanoindentation technique had been used to study the hardness and creep behavior of 6016 aluminum alloys.[Results] The effect of annealing was not very obvious for the hardness, and with the increasing aging time, the hardness of the various samples slightly increased, then significantly decreased, then increased. The creep coefficients fluctuated at different aging time, the creep coefficients n=1.723-2.796, the samples had the optimal value in the 7 d aging. The peak value appeared at 27 d, with the time increasing, the creep coefficients returned to original data, and the rate of deformation decreased to a stable state. But at the same aging condition, the differences of creep coefficients were not obvious.[Conclusion] The hardness of 6016 aluminum alloy treated by different temperature and different aging time varies with aging time. The effect of annealing is weak for the creep coefficient, and the mechanical properties of 6016 aluminum alloys are relatively stable. The 6016 aluminum alloy sheet with "annealing treatment and natural aging", the most appropriate application time is 2 months later.