工业纯钛TA2中低温蠕变特征研究（英文）
发布时间：2018-12-12 11:16
【摘要】：工业纯钛TA2中低温蠕变行为存在显著的温度及应力相关性。基于外加应力水平和蠕变应变的变化关系,确定不同蠕变温度下的门槛应力水平。根据短时蠕变实验数据,利用包含稳态蠕变速率的本构方程外推稳态蠕变速率,而后进行两组相对长时的蠕变实验,证明了工业纯钛中低温蠕变存在稳态蠕变阶段。利用稳态蠕变速率与应力关系,计算出工业纯钛室温蠕变应力指数为6.96,也说明了外推稳态蠕变速率的可靠性。中低温蠕变激活能随着蠕变进行变化不大(≈60 k J/mol),但一直大于以位错为变形主导机制的变形激活能(30~40 k J/mol),表明孪晶对于工业纯钛中低温蠕变发展整个阶段均起重要作用。根据蠕变后试样孪晶结构随温度的变化解释了TA2蠕变行为的温度相关性,同时也证明了孪晶对于TA2蠕变行为的重要性.
[Abstract]:The low temperature creep behavior in commercial pure titanium (TA2) is significantly correlated with temperature and stress. The threshold stress level at different creep temperatures is determined based on the relationship between the applied stress level and creep strain. According to the experimental data of short time creep, the steady state creep rate is extrapolated by the constitutive equation including steady state creep rate, and then two groups of relatively long creep experiments are carried out. It is proved that there is a steady state creep stage in medium and low temperature creep of commercial pure titanium. Based on the relationship between steady state creep rate and stress, the creep stress exponent of commercial pure titanium at room temperature is calculated to be 6.96, which also shows the reliability of extrapolated steady state creep rate. The activation energy of creep at moderate and low temperatures varies little with creep (鈮，
本文编号：2374464
[Abstract]:The low temperature creep behavior in commercial pure titanium (TA2) is significantly correlated with temperature and stress. The threshold stress level at different creep temperatures is determined based on the relationship between the applied stress level and creep strain. According to the experimental data of short time creep, the steady state creep rate is extrapolated by the constitutive equation including steady state creep rate, and then two groups of relatively long creep experiments are carried out. It is proved that there is a steady state creep stage in medium and low temperature creep of commercial pure titanium. Based on the relationship between steady state creep rate and stress, the creep stress exponent of commercial pure titanium at room temperature is calculated to be 6.96, which also shows the reliability of extrapolated steady state creep rate. The activation energy of creep at moderate and low temperatures varies little with creep (鈮，
本文编号：2374464
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