Scanning Rate Extension of Conventional DSCs through Indirect Measurements
Scanning Rate Extension of Conventional DSCs through Indirect Measurements
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DOI：
10.3390/ma12071085
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发表时间：
2019-04-10
期刊：
影响因子：
3.4
通讯作者：
Kessler, Olaf
中科院分区：
文献类型：
--
作者：
Froeck, Hannes;Reich, Michael;Kessler, Olaf
在这项工作中，提出了一种方法，它允许量热信息的测定，因此，有关铝合金的沉淀和溶解行为的信息，在加热速率，以前不能测量。差示扫描量热法（DSC）是一种用于原位记录各种铝合金中溶解和沉淀反应的既定方法。不同类型的DSC设备适用于不同范围的扫描速率。各种可用的商业设备的组合能够覆盖从10（-4）到5 Ks（-1）的加热和冷却速率。然而，在铝合金的一些制造步骤中，高达几百K（-1）的加热速率是重要的。目前，传统的DSC不能实现这些高的加热速率，并且它们对于基于芯片传感器的快速扫描量热法来说仍然太慢。为了填补差距，已经开发了一种间接测量方法，该方法允许在任何热处理的各个点确定关于沉淀状态的定性信息。对EN AW-6082合金样品在淬火温度计中进行不同的快速热处理，并在规定的温度下终止。随后在DSC中再加热样品使得能够分析经热处理的样品的沉淀状态。该方法允许先前不可测量的热处理，以获得关于在短期热处理期间发生的沉淀和溶解反应的信息。
In this work, a method is presented which allows the determination of calorimetric information, and thus, information about the precipitation and dissolution behavior of aluminum alloys during heating rates that could not be previously measured. Differential scanning calorimetry (DSC) is an established method for in-situ recording of dissolution and precipitation reactions in various aluminum alloys. Diverse types of DSC devices are suitable for different ranges of scanning rates. A combination of the various available commercial devices enables heating and cooling rates from 10(-4) to 5 Ks(-1) to be covered. However, in some manufacturing steps of aluminum alloys, heating rates up to several 100 Ks(-1) are important. Currently, conventional DSC cannot achieve these high heating rates and they are still too slow for the chip-sensor based fast scanning calorimetry. In order to fill the gap, an indirect measurement method has been developed, which allows the determination of qualitative information, regarding the precipitation state, at various points of any heat treatment. Different rapid heat treatments were carried out on samples of an alloy EN AW-6082 in a quenching dilatometer and terminated at defined temperatures. Subsequent reheating of the samples in the DSC enables analysis of the precipitation state of the heat-treated samples. This method allows for previously un-measurable heat treatments to get information about the occurring precipitation and dissolution reactions during short-term heat treatments.