Question

In solid state sintering, will atoms diffusing from the particle surface to the neck region by lattice diffusion have slower sintering rate than atoms diffusing from the particle surface to the neck region by surface diffusion?

Answer 1

Solid State sintering is a key process in material sciences and chemical industry. It is the process in which small particles come together and Fuse usually due to application of heat. Sometimes pressure can also be used.

Sintering of glass, ceramics and plastics is a very common process.

There are many mechanisms for sintering all of Which all lead to neck growth and consolidation of powder.

Now comparing lattice and surface diffusion.

Rate will be a result of various factors:

Activation energy: Higher in lattice diffusion.

So clearly surface diffusion will be high at low temperatures and lattice diffusion will be high at high temperatures.

Size of particles: for lower particle size, generally surface diffusion will be preferred.

Factors affecting solid State sintering:

Temperature,pressure, particle size, impurity, density and uniformity.

Rate equations are given in the attached photo.