Predicting the lifetime of fluorosilicone o-rings
Predicting the lifetime of fluorosilicone o-rings
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DOI：
10.1016/j.polymdegradstab.2009.10.005
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发表时间：
2009-12-01
影响因子：
5.9
通讯作者：
Gillen, K. T.
中科院分区：
文献类型：
--
作者：
Bernstein, R.;Gillen, K. T.
对市售氟硅O形环密封进行的长期（长达1000天）加速烘箱老化研究用于预测室温（23 ℃）下的密封寿命。本研究遵循使用等温压缩应力松弛（CSR）技术对挤压O形环材料的力衰减（松弛）。松弛通常是可逆物理效应和不可逆化学效应的复杂混合，但我们利用过度应变方法快速实现物理平衡。这使我们能够集中对主要感兴趣的化学弛豫效应的测量寿命评估。长期研究使我们能够访问相当宽的温度范围（80-138摄氏度），从而改进了加速数据的温度依赖性建模。在最低加速老化温度（80 ℃）下，观察到非阿耳忒修斯行为，有证据表明活化能显著降低。这一观察结果与最近的许多加速老化研究一致，这些研究探索了足够大的温度范围，以观察到类似的非Arrhenius行为。外推预测表明，密封力的显著损失需要在23 ℃下保持50-100年。在23 ℃下进行25年的现场老化结果与加速老化研究中观察到的Arrhenius斜率的显著变化合理雅阁。(C)2009爱思唯尔有限公司保留所有权利。
Long-term (up to 1000 days) accelerated oven-aging studies on a commercial fluorosilicone o-ring seal are used to predict the sealing lifetime at room temperature (23 degrees C). The study follows force decay (relaxation) on squeezed o-ring material using isothermal compression stress relaxation (CSR) techniques. The relaxation is normally a complex mix of reversible physical effects and non-reversible chemical effects but we utilize an over-strain approach to quickly achieve physical equilibrium. This allows us to concentrate the measurements on the chemical relaxation effects of primary interest to lifetime assessment. The long-term studies allow us to access a fairly broad temperature range (80-138 degrees C) which results in improved modeling of the temperature dependence of the accelerated data. Non-Arrhenius behavior is observed with evidence of a significant lowering of the activation energy at the lowest accelerated aging temperature (80 degrees C). This observation is consistent with numerous recent accelerated aging studies that probed temperature ranges large enough to observe similar non-Arrhenius behavior. The extrapolated predictions imply that significant loss of sealing force requires on the order of 50-100 years at 23 degrees C. Field aging results out to similar to 25 years at 23 degrees C are shown to be in reasonable accord with the significant change in Arrhenius slope observed from the accelerated aging study. (C) 2009 Elsevier Ltd. All rights reserved.