Sintering Stages
The kinetics of the process can be broken down into three sintering stages:
1. Initial Neck Growth
Sintering initially causes the particles that are in contact to form grain boundaries at the point of contact through diffusion. This is the point contact stage and does not result in any dimensional changes. The greater the initial density of compaction (increased particle contact and potential grain boundary area), the higher the degree of coherency in the material
In this initial stage of sintering, necks begin to form at the contact points between adjacent particles see Figure 3-5. This stage is therefore referred to as the "neck growth" stage .No change in the dimensions is observed nor does porosity decrease .
Neck formation is driven by the energy gradient resulting from the different curvatures of the particles and the neck, Surface diffusion is usually the dominant mass-transport mechanism during the early stages of neck growth, as the compact is heated to the sintering temperature
Figure (3-5) neck formation
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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