Abstract
In the present paper the authors studied the kinetics of sintering and diffusion in the Cu-Al-Fe-Ni quaternary mixed compacts, where pure aluminium powder was not mixed but alloy powder of Al-Fe or Al-Ni binary system was used in order to prevent the exothermic expansion reported already in the previous papers, and aluminium contents were always kept 10%.
As the present work attaches special importance to examine the diffusivities of nickel contained in different types, i.e., pure nickel, 10AI.3, 7 Ni binary and electroless nickel plated Cu powders, the three different types of Cu-10Al-3, 7 Fe-3, 7 Ni quaternary mixed compacts sintered at 900°C for 1hr were subjected to the X-ray microanalyser, and then we, confirmed that the electroless nickel plated Cu powder showed the best diffusivity of nickel in the sintered compacts, followed by compacts which contained the pure nickel powder. Judging from. the results of X-ray microanalysis and from the dilatometric measurement, it may be proved that the compacts expanded in volume by diffusion of nickel.
When the electroless nickel double-plated Cu powder was used in the quaternary mixed compacts, its chemical composition automatically amounted to Cu-lOAl-6, 9Fe-6, 9Ni, where the rank of Ni-diffusivity reversed the order in Cu-10Al-3, 7 Fe-3, 7 Ni quaternary system above described.
