The Influence of Radiation Modification on the Wear Resistance of Cutters Made of VK-8 Carbide Material

The effect of gamma irradiation on some physicomechanical and tribological properties of VK-8 cemented carbide was investigated. Samples were CNMG 120408-46 indexable cutting inserts (manufacturer Sandvik MKTS, Russia) intended for turning. They were subject to gamma irradiation at various doses from 20 to 200 kGy and in different gaseous environments (air and nitrogen). Irradiation was carried out on an industrial GUD-300M facility using 60Co sources. Tests showed that after irradiation, a decrease in the electrical resistivity of the samples was observed, confirming the hypothesis of microstructure ordering in the irradiated material. Hardness measurements before and after irradiation did not reveal significant changes. However, a significant increase in the wear resistance of the material during cutting of various steels was established, from 1.5 to 6 times, depending on the absorbed irradiation dose, the steel being machined, and the cutting parameters. It is suggested that there exists an “optimal” level of gamma irradiation, below and above which the effect of radiation modification decreases. Determining this level requires separate tests for each material studied. However, general trends of increased wear resistance have been established in this article.