A mathematical model for gravity-induced distortion during liquid-phase sintering

Packing Structure of Particles in a Green Compact and Its Influence on Sintering Deformation

“…Other deformation mechanisms, especially the effects of gravity and nonuniform density, are well studied and documented 1,4,5 . The significance of particle orientation has been reported in some of our recent studies, 2,3,6 and is now being fairly well understood.…”

Influence of gravity on sintering of 3D‐printed powder components

“…For materials, for which large differences between low‐ and high‐viscosity ‐phase densities can be present in the specimen, the gravitational settlement, and a final microstructural gradient can occur, as suggested in different works 21,46,48 . Considering the different viscosity between the two phases (low‐ and high‐viscosity) and the limited and the distance that the high‐viscosity phase can travel, the settling derived from the influence of the gravitational forces during the sintering can be described through the Stokes’ approach.…”

“…The driving mechanism and the effects on the microstructure of the grain migration are the object of many studies. 21,43,44,45,46,47,48,49 In the present work, the assumption proposed by German and Liu 48 is followed. In their study, the grain dispersion and contact engagement during liquid-phase sintering are considered to be the consequences of the action of the shear stresses induced by the specimen's reshaping.…”

“…For materials, for which large differences between low-and high-viscosity -phase densities can be present in the specimen, the gravitational settlement, and a final microstructural gradient can occur, as suggested in different works. 21,46,48 Considering the different viscosity between the two phases (low-and high-viscosity) and the limited and the distance that the high-viscosity phase can travel, the settling derived from the influence of the gravitational forces during the sintering can be described through the Stokes' approach. If the assumptions of the negligible edge effect and grain aggregation can be considered 47 then it is possible to use the Stokes' law for describing the settling velocity of a single grain at low Reynolds number and in an unbounded low-viscosity phase:…”

The Structural Evolution and Densification Mechanisms of Nanophase Separation Sintering

“…This general pathway (second phase precipitation facilitating more rapid mass transport) is conceptually similar to what happens in liquid phase sintering and supersolidus liquid phase sintering [3][4][5][6][7][8][9][10] , but importantly, in NPSS all of this structural evolution occurs completely in the solid state. NPSS therefore avoids the slumping that can occur in some liquid phase sintering systems, and can be used to free-sinter complex green geometries [11][12][13][14] . This provides an advantage to additive manufacturing techniques such as binder jet printing, by maintaing high dimensional tolerences of the as-printed geometry [13,15,16] .…”