Papers by Keyword: Field Assisted Sintering

Abstract: Zirconium diboride and silicon carbide are thought to have a low intrinsic sinterability due to their strong covalent bonds, low bulk and grain boundary diffusivities. ZrB₂-SiC ceramic composites were prepared by a field assisted pressureless sintering process in the present work. The densification behavior and the effect of sintering temperature on microstructure and properties of sintered samples were studied. Pellets were in-situ formed by dry uniaxial pressing in the graphite die at a pressure of 50MPa for 3min and then sintered at a sintering temperature ranged from 1650 °C to 1950 °C with fixed heating rate and holding time. The current, voltage, temperature and displacement data were all collected by the real-time acquisition system. The bulk densities were determined by Archimedes method and the microstructure of samples was characterized by SEM. The onset of some measurable shrinkage of the green body was recorded at around 1400 °C regardless of the sintering temperature and significant shrinkage took place at higher temperature of around 1600 °C. For the sample sintered at 1950 °C, no shrinkage occurred after ~2min holding time. The relative density increased significantly with increasing temperatures and samples could be densified to a relative density of more than 99% at 1950 °C by the field assisted sintering process without obvious grain growth.

Abstract: In this presentation, we show some experimental results of binder-free WC with Nano WC sintered by Pulsed Electric Current Sintering (PECS) process also known as Field Assisted Sintering Technology (FAST). The particle size of WC powder is almost 80 nm. These binder-free WC have extremely hardness and stiffness. However, these mechanical properties are dependent on the sintering condition, e.g., maximum temperature, applied presssure, etc. We show some relationship between mechanical properties and sintering condition to improve to sinter the binder-free WC

Abstract: In this paper, we show some experimental results of binder-free WC sintered by Pulsed Electric Current Sintering (PECS) also known as Field Assisted Sintering Technology (FAST). These binder-free WC have extremely high hardness and stiffness. However, these mechanical properties are dependent on the sintering condition, e.g., maximum temperature, applied pressure, etc. We show some relationship between mechanical properties and sintering condition to improve to sinter the binder-free WC.

Abstract: Melt-spun flakes and air atomised powder of a multi-component Al-Si-Fe-X alloy were consolidated by field assisted (FAST) or spark plasma sintering (SPS) in vacuum using steel dies and punches. Experiments were carried out at 350, 400, 450 and 500°C under applied loads ranging from 81 to 283 MPa. The resulting compacts were microstructurally and mechanically characterized. Ultimate strength values up to 1000 MPa and plastic strains up to 20% were observed during compression tests. The effect of the powder shape on the sintering behaviour is compared. The effect of process parameters such as temperature and applied load on the densification and mechanical properties is discussed. It was found that compacts sintered from melt-spun flakes resulted in a higher strength and ductility than compacts produced from air-atomized powder, sintered under identical conditions.