Overview - ISO 19613:2018 (viscosity of ceramic slurry)
ISO 19613:2018 specifies a standardized method for measuring the viscosity of ceramic slurry using a rotational viscometer. It applies to fine ceramics (advanced/technical ceramics) and covers both instruments that provide a defined shear rate (coaxial cylinder, cone-and-plate, parallel plates) and single-cylinder viscometers that produce an apparent viscosity as a function of angular velocity. The document defines terms (shear stress, shear rate, Newtonian/non-Newtonian behaviour, thixotropy, Bingham plastic), measurement principles, apparatus, calibration, sample pretreatment and reporting.
Key topics and technical requirements
- Measurement principle: Viscosity η = shear stress τ / shear rate γ̇ for viscometers with a defined shear rate; single-cylinder devices measure torque vs angular velocity producing apparent viscosity.
- Measuring geometries: Coaxial double cylinder, cone-and-plate, and parallel plates are detailed (see annexes) for defined shear-rate measurements; single-cylinder options are described for rapid comparative testing.
- Apparatus performance: Instrument torque-measurement accuracy of 2% of full-scale and rotational-frequency accuracy of 2%; viscosity repeatability required to be ±2%.
- Calibration and conditions: Procedures for calibration, temperature control (thermostat/thermometer), selection of geometry/spindle and rotational frequency or shear rate.
- Sample handling: Guidance on sampling, degassing, mixing/dispersion (including ultrasonication), and measurements at fixed shear rate or angular velocity with repeat measurements.
- Result reporting: Expression of results, flow/viscosity curves, and full test-report content requirements.
Practical applications and users
ISO 19613:2018 is used to ensure reproducible, comparable viscosity data for processes and products that rely on ceramic slurries, including:
- Slip casting, tape casting, screen printing, dip and spray coating
- Spray drying feedstocks and polishing/paste formulations
- R&D and formulation development in ceramics and advanced materials
- Quality control and incoming material inspection in ceramic manufacturing
Primary users: materials scientists, process engineers, QC laboratories, testing/calibration labs, instrument manufacturers and standards compliance teams.
Related standards
- ISO/IEC 17025 - competence of testing and calibration laboratories (referenced for laboratory competence)
- ISO 20507 - fine ceramics vocabulary (terminology used)
- ISO 80000-4 - symbols (referenced for notation)
Keywords: ISO 19613:2018, fine ceramics, ceramic slurry viscosity, rotational viscometer, shear rate, cone-and-plate, coaxial cylinder, parallel plates, apparent viscosity, non-Newtonian, thixotropy, Bingham plastic.
Open preview (PDF)Fine ceramics (advanced ceramics, advanced technical ceramics) — Measurement of viscosity of ceramic slurry by use of a rotational viscometer