Materials Science Forum, Vol.453-454, 411-415, 2004
Hydrogen absorption and desorption kinetics in nickel and cobalt alloy powder
Hydrogen absorption and desorption kinetics in polycrystal Ni-55.5-Co-44.5 alloy powder was investigated. Kinetic parameters of hydrogen absorption and desorption in the crystal powder, pressed under pressure of 100 MPa, placed alternately, in an atmosphere of hydrogen (absorption) and then of argon (desorption), were determined by measuring electrical resistivity over time in isothermal conditions at T-1=413 K, T-2=443 K and T-3=463 K. A decrease of the powder electrical resistivity, caused by hydrogen absorption, is significantly dependent on temperature and absorption duration. During the First 120, 100 and 75s at T-1, T-2 and T-3, respectively, a linear dependence of In R on time tau was obtained. The linear dependence of R on tau(1/2) exists within the following time intervals: 120s