The triaxial diagram (clay-flux-silica) is the fundamental framework for ceramic body formulation.
Technical Details
Traditional ceramic science uses the clay-feldspar-quartz triaxial, but replacing feldspar with nepheline creates the clay-nepheline-quartz triaxial — which has a broader and more forgiving vitrification zone. In the triaxial, each corner represents 100% of one component. Moving along the clay-nepheline axis increases plasticity and flux simultaneously. Moving along the nepheline-quartz axis adjusts flux-to-silica ratio. Different product types occupy different zones: porcelain bodies cluster at 30-35% clay, 25-30% nepheline, 20-25% quartz (high flux for full vitrification). Floor tiles occupy 35-40% clay, 18-25% nepheline, 20-25% quartz (moderate flux).
Practical Application
Wall tiles occupy 40-50% clay, 10-18% nepheline, 20-25% quartz (lower flux for controlled porosity). The nepheline triaxial has a wider vitrification zone than the feldspar triaxial because nepheline has more flux per unit and higher alumina — creating a more stable glass phase over a broader composition range. This wider zone means your formulation is more forgiving of measurement errors and raw material variation. When formulating a new body, start at the center of the target zone and adjust based on your firing results. Our technical team can help you position your formulation on the triaxial for your specific product requirements..