Processing of novel glass matrix composites by microwave heating

The application of microwave radiation as the heating source for the processing of glass matrix composites containing metallic particles has been investigated. A borosilicate glass powder was chosen for the matrix. The metal inclusions investigated were molybdenum, tungsten, aluminium, titanium, nickel and iron particles in volume concentration of 10%. The average particle size of primary metallic particles varied between 2 and 50 μm. The microwave heating process was carried out in a self-constructed multimode microwave applicator operating at the 2.45 GHz ISM frequency. For comparison, samples were also made by conventional powder technology and sintering. The microwave- and conventionally-processed samples were characterised in terms of particle distribution, density and glass/metal particle interfacial characteristics. The microwave-processed samples had densities up to 96% of that of the conventionally-processed samples and were obtained in significantly shorter times (7 min versus ∼7 h). In case of glass/Mo composites, a recently developed computational model based on the OOF finite element code was used in order to calculate the residual thermal stresses in the samples.