Comparative study of microstructural and tribological properties of sintered, bulk icosahedral samples

We have investigated a number of quasicrystalline and related samples prepared by sintering under either hot isostatic pressure (HIP) or low uniaxial pressure (LUP). Attention was focused to the influence of the preparation process parameters onto the resulting crystallographic structure and morphology of the phases. Altogether, we found some differences between the two kinds of samples as far as hardness and friction coefficient were concerned. For instance, HIPed specimens containing boron exhibited small rod-shaped precipitates whereas LUPed samples did not. The LUPed specimens revealed better wear resistance and lower friction towards steel and tungsten carbide riders than the HIPed materials. The present study clearly points out that pressure-temperature-composition phase diagrams and preparation processes of quasicrystals, as well as for most other materials, have a significant influence on the final properties which may be eventually used in view of technological applications. (C) 2000 Elsevier Science B.V. All rights reserved.