Microstructural Control of Mg_2Ni Hydrogen Absorbing Alloys by Rapid Solidification and Mechanical Grinding

快速凝固和机械研磨对Mg_2Ni吸氢合金的显微组织控制

基本信息

批准号：
09650757
负责人：
KAMADO Shigeharu
金额：
$ 1.79万
依托单位：
NAGAOKA UNIVERSIYT OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

In this study, for improvement in performance of batteries used in electric vehicles, we paid attention to Mg_2Ni protium absorbing alloy that has high protium absorption capacity, lightweight and low price as compared with the existing protium absorbing alloys. But Mg_2Ni alloy has high protium absorption and desorption temperature and slow hydriding kinetics that must be improved for practical purposes.Therefore, for the purpose of decreasing protium absorption and desorption temperature and improving protium absorption rate, we did a partial substitution of Mg_2Ni by third alloying elements. Mn, Fe, Co, Cu, Al, Zn and Ag which are expected to decrease the absolute value of hydride formation enthalpy of Mg_2Ni alloy were selected as third substitutional elements. The ternary alloys were also rapidly solidified, and mechanically ground in order to homogenize their microstructure. The microstructures of specimens obtained by these processes were observed and their protium absorbing and … More desorbing characteristics were investigated. Obtained results are summarized as followed ; (1) All activated specimens absorb protium at room temperature and their protium contents are higher than those of specimens before activation that causes new surface formation and an increase in reaction area. (2) Hydriding kinetics curves measurements show that rapidly solidified specimens of Mg_2Ni_<0.9>Co_<0.1> and Mg2Ni_<0.9>Fe_<0.1> alloys have the highest reaction rate. It is considered that Fe and Co substitution accelerated the diffusion of protium in these two alloys and rapid solidification cause the fine microstructure. (3) As the elapsed time after taking specimens out from hydrogen atmosphere increases, the protium desorption temperature decreases and desorbed protium contents increases. Microstmctural changes of the hydride from high temperature phase to low temperature phase probably causes this phenomenon. Similar results can be obtained when manually hydride of manually ground specimens after activation shows the same microstructural change, resulting in improvement of the desorption characteristics. (4) By addition of third alloying elements and Ni substitution, both activation energy and enthalpy for dehydriding decreases.From the above results, rapid solidification, mechanical grinding and substitution by 3d transition metals for Ni site in Mg_2Ni crystal structure are effective for improving the protium absorbing and desorbing characteristics of Mg_2Ni alloy. Less

在这项研究中，为了改善电动汽车中用电池的性能，我们注意与现有的吸收蛋白质合金相比，吸收较高的Protium吸收能力，轻质和低价的MG_2NI蛋白质合金。但是MG_2NI合金具有较高的蛋白质吸收温度和缓慢的水合动力学，必须改善用于实际目的。因此，为了降低蛋白质的吸收和解吸温度并提高了蛋白质的吸收率，我们通过第三合金元素对MG_2NI进行了部分取代。 MN，FE，CO，CU，AL，Zn和Ag预计将选择Mg_2Ni合金的氢形成焓的绝对值被选为第三替代元件。三元合金也得到了迅速固化，并在机械上扎根以使其微观结构均匀。观察到通过这些过程获得的标本的微观结构，并研究了它们的蛋白质，并且研究了更多的解吸特征。按照遵循的结果总结了获得的结果；（1）所有活化的标本在室温下吸收蛋白质，其蛋白质含量高于在激活之前引起新表面形成和反应区域增加的样品的含量。（2）水合动力学曲线的测量表明，MG_2NI_ <0.9> CO_ <0.1>和MG2NI_ <0.9> Fe_ <0.1>合金的快速固化标本具有最高的反应速率。据认为，FE和CO订阅加速了蛋白质在这两种合金中的扩散，并且快速固化会导致精细的微观结构。（3）随着从氢气中取出样品后经过的时间增加，protium脱附温度降低，解吸蛋白含量的含量增加。氢化物从高温相到低温相的微刻板变化可能导致这种现象。当激活后手动地面样品显示相同的微结构变化时，可以获得相似的结果，从而改善了解吸特征。（4）通过添加第三合金元素和NI取代，激活能量和焓降低了。从上述结果中，在MG_2NI晶体结构中，NI位点的快速固化，机械磨削和通过3D过渡金属替换为MG_2NI晶体结构中的NI位点有效，可改善蛋白质吸收和吸收特征Mg_2ni Alloy的吸收和desorming特征。较少的