Magnesium-based complex hydride mixtures synthesized from stainless steel and magnesium hydride with subambient temperature hydrogen absorption capability

Abstract The hydrogen absorption-desorption characteristics of composites consisting of 90 wt.% MgH2- 10 wt.% Mg2Ni0.8Co0.2 prepared by ball milling for 30 and 180 min under argon have been investigated. The results obtained have been compared with those for the 90 wt.% Mg-10 wt.% Mg2Ni0.8Co0.2 composite synthesized in the same medium after 30 min of milling. The presence of the Mg2Ni0.8Co0.2 phase has been found to improve the hydriding kinetics of magnesium, the absorption capacity remaining high at temperatures below 573 K. The use of magnesium hydride instead of magnesium has proved to have a favorable effect on the properties of the composites after prolonged activation in an inert medium. It has been established that the absorption-desorption characteristics of the composite 90 wt.% MgH2-10 wt.% Mg2Ni0.8Co0.2 activated mechanically for 180 min are comparable with those of the composite 90 wt.% Mg-10 wt.% Mg2Ni0.8Co0.2 after mechanical activation for only 30 min. The favorable absorption-desorption characteristics of the composites have been explained with the catalytic effect of the additive, the presence of magnesium hydride and the duration of ball milling.

Download Full-text

Doping with Metal and Compound to Improve the Properties of Hydrogen Storage of MgH2

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1015.606 ◽

2014 ◽

Vol 1015 ◽

pp. 606-609

Author(s):

Yan Wang ◽

Shi Wei Wu ◽

Tian Le Li ◽

Shen Shen Li ◽

Zhong Qiu Cao

Keyword(s):

High Temperature ◽

Hydrogen Storage ◽

Transition Metal Oxides ◽

Hydrogen Absorption ◽

Magnesium Hydride ◽

Hydrogen Storage Materials ◽

High Hydrogen ◽

Practical Applications ◽

Hydrogen Capacity ◽

Advantages And Disadvantages

Recently, Magnesium hydride MgH2is one of the attractive hydrogen storage materials because it reaches a high hydrogen capacity. However, the reaction kinetics is too slow and needs high temperature for progressing hydrogen absorption and desorption reactions, which hinders the process of practical applications and it is necessary to improve the hydrogen storage propesties. In this paper, most used or under research methods (Doping with metal and compound) of improving on the hydrogen storage of magnesium hydride are reviewed, in particular to elements substitution, addition of transition metal oxides or fluorine and so on. The advantages and disadvantages of vaious methods of improving on the hydrogen storage of magnesium hydride are compared. The trend of the methods of improving is also introduced.

Download Full-text

Effect of Indentation Load on Vickers Hardness of Austenitic Stainless Steel After Hydrogen Charging

Volume 6B: Materials and Fabrication ◽

10.1115/pvp2014-28280 ◽

2014 ◽

Cited By ~ 2

Author(s):

Osamu Takakuwa ◽

Yuta Mano ◽

Hitoshi Soyama

Keyword(s):

Plastic Deformation ◽

Stainless Steel ◽

Austenitic Stainless Steel ◽

Vickers Hardness ◽

Hydrogen Absorption ◽

Hardness Test ◽

Indentation Load ◽

Hydrogen Charging ◽

Plastic Deformation Behavior ◽

316L Austenitic Stainless Steel

In order to reveal the effect of indentation load on Vickers hardness of austenitic stainless steel after hydrogen charging, the Vickers hardness measurements have been conducted with three different indentation load of 0.49, 1.96 and 9.80 N on the surface of type 316L austenitic stainless steel after hydrogen charging. Relationship between plastic deformation behavior during indentation process and hydrogen absorption behavior was revealed. In the Vickers hardness test, Vickers hardness keeps same value though the indentation load varies. Needless to say, the value did not depend on magnitude of the indentation load before hydrogen charging in the present study. However, the Vickers hardness increased along with hydrogen charging time and, interestingly, the increase in the Vickers hardness due to the presence of hydrogen depends on magnitude of the indentation load. In the load of 0.49 N and 9.80 N, the Vickers hardness has a maximum value of 3.04 and 2.04 GPa which is 1.58 and 1.15 times larger than value of 1.73 and 1.70 GPa before hydrogen charging, respectively. The hydrogen-induced hardening behavior observed by the Vickers hardness tests employing different indentation load would be evaluated by the relationship between the plastic deformation depth and the hydrogen absorption depth.

Download Full-text