Definition of Sintering:
Sintering is the process of enabling atomic diffusion through heating. Addition of thermal energy to the material results in migration of atomic and or ionic components of a material. Upon cooling the realigned crystalline lattice and where present changed distribution of heterogeneous ionic constituents within that lattice structure frequently results in changes is the physical properties of the material from those present in its ‘green´ or pre-sintered state.
A typical example being the realignment of zirconium dioxide through two phase changes from a monoclinic crystalline structure that is stable ambient temperature to a tetragonal lattice structure at about 1000°C and subsequently to a cubic lattice structure at around 2370°C.
Often it is the redistribution of dopants or minor constituents of the heterogeneous mix which exert profound changes on the thermal, mechanical or electrical properties of the sintered material.