The behaviour of porous sinters, during compression and compression with reverse cyclic torsion tests is investigated in the article based on the combination of experimental and numerical techniques. The sinters manufactured from the Distaloy AB powder are examined. First, series of simple uniaxial compression tests were performed on samples with three different porosity volume fractions: 15, 20 and 25%. Obtained data were then used during identification procedure of the Gurson-Tvergaard-Needleman finite element based model, which can capture influence of porosity evolution on plasticity. Finally, the identified Gurson-Tvergaard- Needleman model was validated under complex compression with reverse cyclic torsion conditions and proved its good predictive capabilities. Details on both experimental and numerical investigations are presented within the paper.
This paper discusses the mechanical properties of a material fabricated from commercially available metal powder mixtures designed for use as a metal matrix of diamond impregnated composites. The mixtures with the catalogue numbers CSA and CSA800 provided by a Chinese producer are suitable for experimental laboratory testing. The specimens were fabricated in a graphite mould using hot pressing. The material was tested for density, porosity, hardness, and tensile strength under static loading. A scanning electron microscope (SEM) was used to analyze the microstructure and cleavage fracture of broken specimens. It was essential to determine how the chemical composition and the fabrication process affected the microstructure and properties of the material. The properties of the sinters were compared with those of hot pressed specimens fabricated from sub-micron size cobalt powder (Cobalt SMS). Although the as-consolidated material is inferior to cobalt, it displays a favourable combination of hardness, yield strength and ductility, and seems to have a great potential for moderate and general purpose applications.
The paper presents the results of preliminary studies on the properties of products made by vitrification of waste containing fly ashes from sewage sludge incineration. The performed tests of hazardous substances leached from the ashes, as well as the results of other laboratory tests confirmed the efficacy of vitrification. It has been found that the resulting products (sinters) could be used as a substitute aggregate for road foundations.