Vyasaraj Manakari; Gururaj Parande; Mrityunjay Doddamani; Ganesh Kumar Meenashisundaram; Manoj Gupta
Abstract
Lightweight composite materials possessing higher damping capabilities are of great interests to material designers satisfying ever changing demands in automotive, aerospace and marine sectors. Besides having lowest density in metals regime, magnesium exhibits superior mechanical properties. Specific ...
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Lightweight composite materials possessing higher damping capabilities are of great interests to material designers satisfying ever changing demands in automotive, aerospace and marine sectors. Besides having lowest density in metals regime, magnesium exhibits superior mechanical properties. Specific properties can still be enhanced by reducing the density further with development of magnesium based syntactic foams. Present work deals with processing and experimental characterization of glass microballoon (GMB) reinforced magnesium (Mg) composites. Hollow glass microspheres (5, 15 and 25 wt.%) reinforced magnesium syntactic foams were synthesized in magnesium matrix using the disintegrated melt deposition (DMD) method and their damping properties are investigated. The addition of glass microspheres enhanced the damping and loss factors by 370% and 12.5 times respectively for the highest filler loading as compared to pure magnesium. Further, increase in damping is correlated with microstructural changes arising due to the presence of the hollow glass microspheres. Elaborate discussion is presented on underlying mechanisms and different phases formed during processing.
Ankur Jain; Pragya Jain; Shivani Agarwal; Paola Gislon; Pier Paolo Prosini; I.P. Jain
Abstract
Magnesium hydride is a promising material for hydrogen storage due to its high storage capacity i.e.7.6wt%. But its high stability i.e. high desorption temperature (~350? o C) limits its practical application towards hydrogen economy. Moreover the kinetics is also too slow even at high temperatures. ...
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Magnesium hydride is a promising material for hydrogen storage due to its high storage capacity i.e.7.6wt%. But its high stability i.e. high desorption temperature (~350? o C) limits its practical application towards hydrogen economy. Moreover the kinetics is also too slow even at high temperatures. Composite formation with Zr based laves phase alloys, especially ZrCr2 family, is an effective method to improve the hydriding properties of MgH2. This work presents the synthesis, structural, morphological, and hydrogenation properties of Mg-x wt% ZrCrMn composites. Both phases i.e. Mg & ZrCrMn remain their presence after milling and several hydriding cycles as well. SEM results suggest the homogeneous distribution of alloy particles on Mg matrix. Pressure composition temperature (PCT) analysis shows a reduction in desorption temperature down to 250 o C for these composites. TG experiments suggest a total hydrogen capacity of 5.9% and 4.35% for x =25, 50 in Mg-x wt% ZrCrMn composites respectively. The enthalpy of hydride formation is also calculated using Van’t Hoff plots, which is found similar to the parent material i.e. MgH2. A remarkable enhancement in the kinetics of hydrogen absorption / desorption is reported here by forming these composites.
