HIPING CONDITIONS FOR PROCESSING OF METAL-MATRIX COMPOSITES USING CONTINUUM THEORY FOR SINTERING .2. APPLICATION TO FIBER-REINFORCED TITANIUM-ALLOYS

Processing of metal matrix composites (MMC) by hot isostatic pressing (HIPing) of fibres coated with a titanium alloy is discussed using the continuum theory for sintering. For the viscosity of titanium at HIPi ng conditions an exponential equation based on experimental data chose n From literature is used. The computations are performed for differen t fibre diameters, fibre volume fractions, initial porosity, initial d imensions of large imperfections and HIPing conditions. The parameters determined are: the final radius of imperfections, the final porosity , the time for a complete consolidation and additional time compensati ng a lower HIPing temperature. The influence of pressure and temperatu re rate on the consolidation behaviour is discussed. For composites wi th the gamma-TiAl-alloys as matrix the accumulated tangential deformat ion is determined and the application of a second matrix coating on th e fibres as a ''consolidation aid'' is discussed.