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

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