1.5.6 Sintering Models
Matter transport during sintering is driven by chemical potential gradients arising from differences in the curvature of the free surfaces in the compact of particles. When compared to atoms under a flat surface at the same temperature and composition, the atoms under a convex surface have a higher chemical potential while the atoms under a concave surface have a lower chemical potential. This gradient in the chemical potential produces a driving force for matter transport from the (convex) particle surfaces and from the grain boundaries between the particles to the (concave) necks between the particles (Figure 1.5). Mathematical models have been developed to analyze the rate of matter transport along these paths. The models can be classified into three types: (a) analytical models; (b) scaling laws; and (c) numerical models.
1.5.7 The Sintering Stress
The formulation of the driving force for sintering, the sintering stress, in terms of an equivalent external stress. In the loading dilatometry experiments, the hydrostatic component of the applied uniaxial stress is small compared to the sintering stress, so that the sintering mechanism of the loaded powder compact is expected to be identical to that for a freely sintered compact.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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