Pressureless sintering of mullite/Mo composites

Mullite of stoichiometric composition (3Al(2)O(3).2SiO(2)) is a highly attr active candidate material for structural applications. In this study, the e ffect of Mo addition to mullite matrix has been investigated. Mullite/Mo co mposites have been densified at 1600 degreesC for 2 h by pressureless sinte ring. Conditions have been made to sinter the samples in a non-oxidizing at mosphere. No traces of oxides have been identified by XRD analysis after po lishing the specimens. Young's modulus increases with increase in Mo conten t and hardness decreases with the Mo content by obeying the rule of mixture s. Fracture toughness has been increased from 1.7 to 3.5 MPa.m(1/2) for the 30 vol%. Mo containing composites, which is twice that of monolithic mulli te, Microstructures of the sintered samples were analyzed using SEM.