Zhang, DeliangKoch, C.C.Scattergood, R.O.2010-07-192010-07-192009Zhang, D., Koch, C.C. & Scattergood, R.O. (2009). The role of new particle surfaces in synthesizing bulk nanostructured metallic materials by powder metallurgy. Materials Science and Engineer: 516(1-2), 270-275.https://hdl.handle.net/10289/4162The role of new particle surfaces in synthesizing bulk nanostructured metallic materials by consolidation of nanostructured powders and nanopowders is analysed by developing three simple mathematical equations for calculating the α factor for different thermomechanical powder consolidation processes such as hot pressing, high pressure torsion and extrusion. The α factor is the fraction of the area of the powder particle surfaces newly formed during consolidation over the total particle surface area which includes both pre-existing surface area and the newly formed surface area. It is demonstrated that the values of the α factor calculated using these equations can be reasonably used to predict the level of inter-particle atomic bonding that is likely to be achieved through cold-welding by the above mentioned typical thermomechanical powder consolidation processes which also include high energy mechanical milling. Based on this analysis, it is clear that uniaxial hot pressing of a powder compact in a rigid die at low homologous temperatures (<0.5Tm) is unlikely to be capable of achieving a sufficiently high level of inter-particle atomic bonding for producing a high quality consolidated material, while processes involving a large amount of plastic deformation have such capabilities.ennanostructuremetallic materialspowder consolidationparticle surfacesinter-particle atomic bondingJournal Article10.1016/j.msea.2009.03.024