Papers by Keyword: Sintering Stress

Abstract: Aiming at the modification of the sinterability of metal/ceramic powder mixtures, the influence of the homogeneity in microstructure on the sintering behavior is examined. Ni/Al2O3 specimens, with ratios ranging from 0/100 to 100/0, are prepared by compaction through two different procedures of mixing and granulating, to change the degree of particle dispersion. The sintering stress and the viscosity of the specimens are measured by sinter-compression tests to consider the sinterability from the viewpoint of both driving force and resistance. The sintering rate of the inhomogeneous compacts, with agglomeration of powder particles, is larger than that of the homogeneous compacts. This is because the viscosity becomes low, but the sintering stress does not change much by inhomogenizing the microstructure.

Abstract: The sintering stress is related to the thermal stability of porous structure. The sintering stress for a given porous structure in equilibrium can be calculated by three methods theoretically; the energy difference method, the curvature method, and the force balance method. The sintering stresses by three different methods were exactly the same for the idealized porous materials in equilibrium, in which the pore surface had a constant curvature at any point. The porous material does not spontaneously shrink when the sintering stress becomes zero or negative. The sintering stress will be used to design optimal porous structures with improved thermal stability.