Sintering energy conservation in extrusion-based 3D printing of porcelain ceramics blended with copper and allied alloys: A sustainable approach

Abstract

This study investigates the use of copper particles in porcelain ceramics for reduced sintering temperature effort as a part of a sustainable environment. Porcelain powder is mixed with 10 wt% copper powder, 25.3 wt% water, and 12.6 wt% ethanol, and the rheological characterization is made. The rheological characterization of the initial slurry and the phases that evolved during sintering at various temperatures were studied. With suitable rheology of slurry, prototype parts are manufactured by 3D printing. The length-to-diameter ratio of the nozzle, stand-off distance, and type of underlying substrates are also observed to influence the printability. The sintering is performed in the temperature range of 500 °C–1200 °C. The sintered parts were characterized for various phases in the selected temperature range. In addition, a study was conducted to find sintering temperature variation with the percentage of copper addition made by mixing brass and bronze with multiple compositions of zinc and tin, respectively. Once the standards are established with copper in a research-based printer, porcelain with other elements is printed on a bulk printer, ensuring repeatability. The retention of natural binder kaolinite at various temperatures is also verified. This study also opens a new dimension for sustainable multi-material ceramic 3D printing with increased solid loading at ease with required customization. The results showed that adding copper particles to the porcelain powder reduced the sintering temperature by up to 200 °C. The study concluded that adding copper particles to porcelain is a promising method for sustainable 3D printing of ceramics.