Thermal residual and mechanical stresses generated by hot isostatic pressing, cooling and subsequent mechanical loading of SCS6/Ni3Al and SCS6/Ti3Al composites with uncoated and carbon-coated fibres have been simulated by micromechanical modelling. The solutions were found in a periodic hexagonal array model of the microstructure with the finite element method. The intermetallic matrices were assumed to be elastic-plastic, with temperature-dependent properties. The fibre and coating were assumed to be elastic. Local stress fields and overall response were found for several processing sequences. The results suggest that plastic deformation of the matrix during cooling from fabrication temperatures reduces residual stresses. The Ni3Al matrix system yields more easily than the Ti3Al system. HIP programmes that promote such yielding are proposed and analysed in both systems. Compliant and expansive fibre coatings tend to reduce the thermal stresses, but may also enhance the interface stresses in the matrix under overall mechanical loads.