K. Brand et W. Schatt, SOLID-PHASE SINTERING OF POWDER MIXTURE C OMPACTS WITH COMPLETE SOLUBILITY OF THE COMPONENTS, Zeitschrift fur Metallkunde, 84(12), 1993, pp. 893-898
The influence of interdiffusion (homogenization) on the densification
was investigated in the systems Ni - Co and Ni - Cu, whereby the diffu
sion coefficients of the single elements differ significantly from eac
h other (D(Co) almost-equal-to D(Ni); D(Cu) > D(Ni). Besides the nonis
othermal and isothermal shrinkage as well as their velocity, the devel
opment of the degree of homogenization and the defect state was determ
ined. The shrinkage behaviour of Ni - Co compacts lies between those o
f Ni and Co compacts. There is a nearly linear correlation between shr
inkage and concentration. Therefore, the densification process of the
mixtures is dominated by the same defect-activated material-transport
mechanisms like in single-component systems. The interdiffusion exerts
only a minor influence. However. in Ni - Cu sintering samples, which
have a mean composition as well as a ''Cu < 50 %'' composition, the in
terdiffusion leads to a deviating behaviour. This is caused by the res
ulting Cu diffusion stream and this again results in a volume increase
of the former Ni particles and the diffusion porosity in the former C
u particles.