Sintering Neck Growth
The enlargement of the contact area between adjacent powder particles through diffusion processes during the initial phase of thermal input. This determines the mechanical stability of the pre-assembly.
Sinter neck growth happens when the powder grains start to fuse at the contact points during sintering. The atoms then migrate across the surface and form solid bonds there, causing the powder to slowly grow together into a solid part. If that doesn't work properly, you won't get a decent bond between the grains and the part will become brittle or tear away under load. Conversely, it's also not good if the parts fuse too strongly; then the structure becomes too dense and you get problems with permeability or debinding. For the workshop, this means: you have to carefully coordinate temperature and holding time during sintering and keep an eye on the powder composition. If you go too hot or too long, you lose control over the structure.