Properties of Fe-Cu matrices for diamond impregnated tools

摘要

The recent tremendous price cuts on the diamond supply side along with parallel developments in diamond coating technology, enabling the use of inexpensive but reactive matrix materials, like iron, have brought pressure on the diamond tool industry to substitute expensive cobalt-base matrices with cheaper materials that would exhibit excellent consolidation behaviour, good mechanical properties and field performance similar to cobalt. The main objective of the work described in this paper by M. Zak-Szwed, J. Konstanty and W. Ratuszek was to determine the effects of powder composition and consolidation conditions on microstructure and mechanical properties of iron-base, cobalt-free materials to be used as matrices in diamond impregnated tools. Pre-alloyed Fe-Gu and Fe-Cu-Sn-Sm_2O_3 powders were used for the experiments. The powders were consolidated by both the hot press and cold press/sinter routes. All as-consolidated materials were subjected to density measurements and Rockwell hardness test. The hot pressed specimens were also tested for bending properties and examined by scanning electron microscopy and X-ray diffraction. Both powders exhibited excellent densification behaviour. The near full densities were achieved at 650 deg C and 850 deg C after densification by the hot press and cold press/sinter process, respectively; whereas consolidation at higher temperature, in the austenite stability range, led to a marked rise in ductility of the material at the expense of its mechanical strength. The examined materials showed a fine-grained microstructure regardless of consolidation conditions. For both powders an optimum hot pressing temperature was found to assure a desirable combination of high hardness and yield strength, and good ductility of the fully dense material.