Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 2001

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: mechanically alloyed powders

Sortuj według:

Ogranicz wyniki do:

Comparative studies of surface composition in polycrystalline and nanocrystalline LaNi4.2Al0.8 alloys.

Smardz L., Jurczyk M., Smardz K., Nowak M.

Inżynieria Materiałowa

2001

R. XXII, nr 5

854-856

The surface chemical compositions of nanocrystalline LaNi4.2Al0.8 alloys was studied by Auger electron spectroscopy and compared to that of a polycrystalline sample. Results showed that the surface segregation of La atoms in the mechanically alloyed nanocrystalline LaNi4.2Al0.8 alloy is stronger compared to that of polycrystalline powders from arc-melted ingots. On the other hand, the level of oxygen impurities trapped in the mechanically alloyed powder during the processing is practically the same as in the arc-melted ingots. Small amounts of Fe impurities, which strongly segregate to the surface, could be responsible for the observed a little lower hydrogen storage capacity of the MA nanocrystalline LaNi4.2Al0.8 alloy compared to that of polycrystalline samples.