The influence of the liquid phase on anisotropic dimensional change on sintering iron alloys

The effect of the presence of a liquid phase during sintering on anisotropy has been investigated by dilatometry on specimens that have been obtained cutting prismatic green parts in different directions: parallel to the compaction direction (longitudinal), and perpendicular to the compaction direction (transverse), respectively. The spreading of the liquid phase occurs easily throughout the particle contacts in the transverse region and all the sintering phenomena related to the liquid phase are enhanced along this direction: swelling and subsequent shrinkage in iron-copper, shrinkage in iron-phosphorus, compensating for the larger shrinkage along the longitudinal direction that occurred in the solid state.