Effects of annealing temperatures on the physicochemical properties of nickel-phosphorus deposits

[[abstract]]©2003 Elsevier - The dependence of physicochemical properties, including microhardness, magnetism, morphology, crystalline information, roughness factor and hydrogen evolution ability, on the phosphorus content, varying from 0 to 28 atomic percentage (at.%), of Ni-P deposits with annealing in air at eight temperatures (i.e., 100, 200, 300, 400, 500, 600, 700 and 800°C) were systematically compared. The microhardness reached a maximum at 400°C due to the crystallization of Ni and Ni3P at 400°C and the significant diffusion of Cu into the Ni-P deposit at temperatures greater than or equal 500°C, confirmed by the depth profiles of Ni, P, Cu and O elements. The paramagnetism of Ni-P deposit was gradually transformed into ferromagnetism at 400°C, attributable to the phase separation of Ni and Ni3P. The roughness factor, Ra, of the deposits with P contents [less-than or equal to] 12at.% were increased with increasing the annealing temperature at temperatures less than or equal 400°C but Ra of the deposits with 17-28at.% of P is approximately independent of the annealing temperature. The rate of hydrogen evolution decreased with increasing the annealing temperature because the specific activity (i/Ra) of the Ni-P deposits was decreased with increasing the annealing temperature.[[department]]化學工程學