Improvement of Hydrogenation and Dehydrogenation Kinetics of As-Cast AZ91 Magnesium Alloy via Twin Parallel Channel Angular Extrusion Processing
Improvement of Hydrogenation and Dehydrogenation Kinetics of As-Cast AZ91 Magnesium Alloy via Twin Parallel Channel Angular Extrusion Processing
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DOI：
10.3390/cryst12101428
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发表时间：
2022-10
期刊：
影响因子：
2.7
通讯作者：
M. Abdi;R. Ebrahimi;E. Bagherpour
中科院分区：
文献类型：
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作者：
M. Abdi;R. Ebrahimi;E. Bagherpour
本研究采用双平行通道转角挤压（TPCAE）工艺改善铸造AZ91镁合金的储氢性能。加工在不同的温度下进行，从340 °C到200 °C。在三个不同的温度下，使用Sievert型装置进行氢吸收和解吸试验。作为TPCAE处理的结果，实现了吸收动力学的显著改善。最大吸收能力为6.1重量%在2000 s的时间跨度内，对于具有在250 °C下补充的三个处理通道的样品实现。此外，脱氢的动力学显著改善，并且对于所有处理的样品，在最大2500 s的时间跨度内在350 °C下实现完全解吸。通过计算加氢活化能和评价微观结构的变化，发现实施足够的热机械功水平沿着在较低的温度下施加过程的最后道次导致活化能的降低和加氢动力学的改善。
In the current study, Twin Parallel Channel Angular Extrusion (TPCAE) as a developed SPD processing technique is used to improve the hydrogen storage properties of AZ91 cast alloy. The processing is conducted at different temperatures, ranging from 340 °C down to 200 °C. The hydrogen absorption and desorption tests are conducted kinetically at three different temperatures, using a Sievert-type apparatus. Remarkable improvement in the absorption kinetic is achieved as a result of the TPCAE processing. A maximum absorption capacity of 6.1 wt.% within a time span of 2000 s is achieved for the sample with three passes of processing complemented at 250 °C. Also, the kinetic of dehydrogenation is improved significantly and complete desorption at 350 °C is achieved for all the processed samples within a time span of maximum 2500 s. By calculating the activation energy of hydrogenation and evaluating the microstructure changes, it is found that implementing sufficient thermomechanical work level along with applying the last pass of the process at lower temperature results in a reduction of the activation energy and improvement of the hydrogenation kinetic.