Effect of geometric work-hardening and matrix work-hardening on workability and densification of aluminium–3.5% alumina composite during cold upsetting

The densification is a measure of deformation in upset forming of Powder Metallurgy (P/M) processes. A complete experimental investigation on the deformation behaviour of aluminium–3.5% alumina powder composite has been discussed for the case of triaxial stress state condition. Cold upsetting of aluminium–3.5% alumina composite with and with no annealing having different initial preform relative density and with different aspect ratio was carried out and the densification behaviour of the preform under triaxial stress state condition was determined. A new true strain considering the effect of bulging was taken into account for the case of determination of the hoop strain. Plots made for different preforms were analyzed for the densification behaviour of preforms considering the effect of both geometrical work-hardening (GWH) and the matrix work-hardening (MWH).