Optimization of VK10-HOM cemented carbide mixture pressing modes

The article presents the results of a study on pressing and sintering of cemented carbide plates in order to increase the durability of metal-cutting tools.The substantiation and optimization of the cemented carbide mixture pressing conditions is shown.Various plasticizers were used in the preparation of the mixture.Pressing modes and results on pressing force and elastic aftereffect coefficient are given.After sintering the samples, the microstructure, porosity, density, and hardness are determined.Microstructures are shown with the use of plasticizers SKD II (BR-1203) and PEG-1500.According to the granulometric composition, the initial mixture had an average particle size of 0.7601 microns.The pressing was carried out with preliminary vibration-mechanical treatment of a mold filled with a cemented carbide mixture with a plasticizer.The dependences of the density and the coefficient of elastic aftereffect on the pressing pressure are obtained.The variation ranges of pressing speed and pressure were as follows: pressing speed -from 3 to 15 kN/s, pressing pressure -from 100 to 900 MPa.Prov iding pressing speeds in the required pressure range was carried out on presses with loads up to 100 kN and up to 1250 kN.It has been established that polyethylene glycolbased plasticizers are preferable in terms of elastic aftereffect, density and porosity.When optimizing the parameters of pressing the VK10-HOM mixture in the selected intervals of varying factors, a plan for a complete two-factor threelevel experiment for each type of plasticizer was drawn up.The density of compressed samples and the coefficient of elastic aftereffect were chosen as the optimization criteria.In the joint analysis of experimental response surfaces, a compromise task to determine the optimal parameters of the pressing process was solved for optimization criteria.The microstructure of plates obtained under the optimal pressing mode, using PEG-1500 plasticizer at sintering temperature of 1390 °C, shows low porosity, absence of undesirable K-phase at higher values of density and hardness.