Advances in Strength Properties Testing of Sintered Tool Materials

摘要

Brief review of most important tests of hardmetals strength properties together with their practical usage for a quality control and an informative quantity in research work is presented. The selected methods of testing strength properties are analysed in the paper with particular regard to: transverse rupture strength, fracture toughness, indentation fracture toughness and splitting (or "indirect") tensile strength test. The fracture toughness was tested on the single edge notched beam (SENB) specimens with notch precracked using the "zapping effect" during spark discharge. The experiments were carried out at room and elevated temperature up to 600℃. For the comparison with the commonly used indentation fracture toughness (Palmqvist/Vickers or Knoop) an alternative so-called indentation/strength in bending (ISB) technique was included to tests. An automatic grating interferometry (AGI) to examining in plane displacements within the Palmqvist and median/radial cracks was used.