Microstructure and protium absorption/desorption characteristics of Mg2Ni/LaNi5 composite

In this study, an attempt is made to form composites that have well-bonded structure consisting of Mg2Ni alloy that has high hydrogenation capacity and LaNi5 alloy that is capable of protium absorption/desorption at low temperature, by mechanical alloying (MA) or pulse-electric-current-sintering (PECS) for utilization of synergy effect to acquire both high capacity and ability to absorb/desorb protium at low temperatures. During the absorption process, protium content of MA+PECS and MA specimens reaches 0.9 and 1.2mass% at 80degreesC, respectively, which is over the theoretical value for LaNi5 phase, indicating the occurrence of synergy effect. During the desorption process, MA+PECS specimen start desorbing protium of 0.73mass% at about 100degreesC. The value of 0.73mass% is higher the protium desorption content of LaNi3 phase while 100degreesC is lower than the usual desorption temperature of Mg2Ni phase. Consequently, the result confirms the occurrence of synergy effect on absorption/desorption process of the obtained composites.