Abstract
The growing demand for improved operational efficiency of cast components used in various types of equipment necessitates the development of advanced casting technologies. One of the key challenges currently faced by the foundry industry is enhancing the surface quality of castings and reducing rejection rates caused by casting defects. These requirements can be effectively met by castings produced using shell mold casting technology. Sand–resin mixtures are used for their production. Foundry molds made from such mixtures make it possible to obtain high-quality castings from various alloys. However, their widespread industrial application is limited by the relatively high cost of the binder, namely pulverbakelite. The influence of pulverbakelite content on the properties of sand–resin mixtures during shell mold formation under variational static pressure was investigated. It was established that pressure variation during the molding process increases mold strength and improves surface quality while maintaining the required level of gas permeability. The optimal binder content was determined to be 4–6%, which makes it possible to reduce binder consumption without deteriorating the mechanical and technological characteristics of the mold. With respect to novelty, it should be noted that previous studies addressed individual aspects of variable pressure application. In the present article: a wider range of pulverized bakelite content (3–9%) was investigated; the relationship between binder content, strength, and gas permeability was established; the optimal binder content range (4–6%) was determined; and microstructural analysis was extended to include composition and pressure regimes. Thus, the present work significantly extends previous findings and provides a more comprehensive investigation.