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.
This paper deals with computer modelling of the retention of a synthetic diamond particle in a metallic matrix produced by powder
metallurgy. The analyzed sintered powders can be used as matrices for diamond impregnated tools. First, the behaviour of sintered cobalt
powder was analyzed. The model of a diamond particle embedded in a metallic matrix was created using Abaqus software. The
preliminary analysis was performed to determine the mechanical parameters that are independent of the shape of the crystal. The
calculation results were compared with the experimental data. Next, sintered specimens obtained from two commercially available powder
mixtures were studied. The aim of the investigations was to determine the influence of the mechanical and thermal parameters of the
matrix materials on their retentive properties. The analysis indicated the mechanical parameters that are responsible for the retention of
diamond particles in a matrix. These mechanical variables have been: the elastic energy of particle, the elastic energy of matrix and the
radius of plastic zone around particle.
This article discusses results of an analysis of mechanical properties of a sintered material obtained from a mixture of elemental iron, copper and nickel powders ball milled for 60 hours. The powder consolidation was performed by hot pressing in a graphite mould. The hot pressing was carried out for 3 minutes at 900 °C and under a pressure of 35 MPa. The sintered specimens were tested for density, porosity, hardness and tensile strength. Their microstructures and fracture surfaces were also examined using a scanning electron microscope (SEM). The study was conducted in order to determine the suitability of the sintered material for the manufacture of metal-bonded diamond tools. It was important to assess the effects of chemical composition and microstructure of the sintered material on its mechanical properties, which were compared with those of conventional metal bond material produced from a hot-pressed SMS grade cobalt powder. Although the studied material shows slightly lower strength and ductility as compared with cobalt, its hardness and offset yield strength are sufficiently high to meet the criteria for less demanding applications.