The possibility of using an evaporable plastic block mold made by 3D printing for forming a hard alloy milling cutter

The article studies the pressing of WC – 5 TiC – 10 Co hard alloy milling cutter blanks into evaporable polylactide molds made by 3D printing and subsequent sintering of samples in a vacuum furnace. The content of plasticizer (rubber) in powder mixtures for pressing blanks of WC – 5 TiC – 10 Co alloy samples is, % (vol.): 13; 23; 38; 48. Disposable molds for pressing milling cutters are made of polylactide by surfacing. Experiments show that such plastic molds enclosed in a steel shell can withstand a pressure of 400 MPa. The dependences of the integrity and density of blanks and sintered samples on the pressing pressure and concentration of plasticizer are investigated. It is demonstrated that an increase in its concentration from 13 to 48%(vol.) leads to a decrease in the relative density of sintered samples from 99.2 to 96.0% due to an increase in the concentration of free carbon inclusions. The results of the research demonstrate that if a plasticizer concentration is less than 38%(vol.), the samples are destroyed due to thermal stresses. The products made with 48%(vol.) plasticizer retain their integrity. The microstructures of the surface, longitudinal and cross sections of sintered milling cutters are investigated. Despite the fact that the required density is achieved, surface defects and high porosity (due to the presence of free carbon and defects formed during mold deformation) do not allow to make products that meet modern requirements. Further research is needed to produce milling cutters that meet modern requirements using the proposed method.The research was supported by RGNF grant No. 23-29-00063.