Optimization of the technology for fusing hard-alloy electro-erosion powder materials

Purpose. Optimization the sintering process of an electroerosion charge obtained by the method of electroerosion dispersion of tungsten-free hard alloy waste in an carbon-containing working fluid. Methods. Tungsten-free carbide waste was selected as the starting material for the study. The dispersion process was carried out in a carbon-containing working fluid—methanol. A setup whose design is protected by Russian Federation Patent No. 2449859 was used for electrical discharge dispersion. The electro-erosion particles were consolidated using the Spark Plasma Sintering system Model 25-10 (SPS 25-10) manufactured by Thermal Technology. The consolidation modes (temperature, pressure, and exposure time) for the new alloy were selected based on the criterion of achieving the maximum microhardness of the sintered samples using the 2³ full factorial experiment method. Results. The measurements carried out showed that the microhardness of samples sintered by the SPS method from powder dispersed in a methyl alcohol medium is on average 1415 HV. Conclusion. The determination of optimal parameters of the process of obtaining tungsten-free hard alloy by spark plasma sintering of particles according to the microhardness of sintered samples by conducting a full factor experiment of type 23 has been carried out. The following parameters of the spark plasma sintering unit have been selected as factors: temperature, pressure and holding time. Optimal parameters of the unit operation have been determined for the electroerosion material previously obtained from TFHA waste in carbon-containing medium - distilled water. Based on the results of a series of experiments, the optimal sintering conditions were determined to achieve the maximum microhardness values. The maximum microhardness of the composite with electro-eroded particles obtained in a methanol environment reached 1427 HV, which is 17% higher than that of the base industrial alloy. This maximum was achieved after sintering at 1200 °C under a pressure of 40 MPa with a 5-minute exposure.