Liquid flow into the interior of W-Ni-Fe compacts during liquid phase sintering

During liquid phase sintering of W-Ni-Fe alloy, liquid is sometimes observed to flow into the specimen's interior and porous regions remain near the surface. The phenomenon occurs concurrently with a rapid overall densification. It is proposed that the liquid flow occurs when the closed pores in the interior are filled with liquid while the liquid menisci at the surface recede. It is also shown by a critical experiment that this effect does not arise from a temperature gradient in the compact during sintering.