Interfacial Criteria to Avoid Pushing of Particles during Solidification of Metal Matrix Composites

Abstract

The interfacial criterion to avoid pushing of particles during solidification of ceramic reinforced metal matrix composites (MMCs) at low rates of the solidification has been found as: i for liquid alloys with at least one interface-active solute (at the melt/particle interface) the engulfment of particles is always ensured by the interfacial energy gradient caused by solute build-up; ii. for pure metals and for alloys with no interface-active components engulfment is ensured if the following condition is fulfilled: Δσ = 2σ cs - σ cl - σ sl < 0 (where σ is the interfacial energy, J/m 2 , and lower indexes indicate the phases in contact: c is for ceramic particle, s is for solid metal and l is for liquid metal A new model is derived to estimate the interfacial energy between solid metal and solid ceramics. Based on this model, the pushing-engulfinent diagrams have been constructed.