Abstract
The particle coarsening in Fe-20 wt% Cu alloy, in which the solid particles are bonded to each other by a number of interparticle welds, has been studied in the temperature range between 1100 and 1250°C. The other structural properties that change with particle coarsening, such as the size and the mean free path of solid particles, the average size and the number of interparticle welds were determined by quantitative microscopic analyses for the specimens sintered at 1150°C. The mechanism of particle coarsening is analyzed on the basis of the experimental results obtained. The particle coarsening can not be explained by the Lifshitz-Slyozov-Wagner theory alone. The increase in the size of the interparticle welds and the decrease in the number of them suggest that solid particles coalesce as a consequence of the weld growth. The kinetic equation of the growth of the interparticle welds during particle coarsening is derived, and it is proposed that the particle coarsening occurs substantially due to the coalescence of solid particles. The discontinuity in size distributions of solid particles is also discussed in terms of the coalescence hypothesis.
