CUMITHERM®– A State-of-the-art Zero Expansion Ceramics and its Applications
Santanu Mandal, Suresh Kumar Chatakonda, Arijit Chatterjee, Shyam S Rao
Abstract
Carborundum Universal Limited – Industrial Ceramic (CUMI – IC) Division design, develop, manufacture and supplies technical ceramic products for industrial applications. The applications include wear-resistance, corrosion-resistance, electrical insulation, dielectrics, thermal and thermal shock resistance, ballistic protection etc. CUMI – IC division has recently developed through in-house R&D and launched CUMITHERM® which is a reaction-sintered aluminium titanate (Al2TiO5) products for thermal and thermal shock resistance applications. CUMITHERM® has near-zero/negative coefficient of thermal expansion, non-wettability to molten metal, excellent thermal insulation and very good mechanical and thermo-mechanical properties in this class of material. The mechanical performance improves with increase in temperature and gets doubled at around 9000C. The unique properties like dimensional stability over a wide range of temperature and increase in strength with temperature are very rare in the field of material science. The reaction sintered aluminium titanate phase is achieved by combining high-purity alumina and titania along with appropriate stabilizing agent and sintering additives in a precision controlled reaction sintering process and engineering a micro-fissures microstructure. Therefore, CUMITHERM® is ideally suited for non-ferrous molten metal handling and conveying applications like molten metal handling, conveying and in cast-house for primary processing of aluminium metals and secondary processing like non-ferrous foundries. The casting spouts and control rods, retainer rings, nozzles, launders, thimbles, dosing tubes, tapping plug and rings, insulation rings, riser tubes, sprue-bushes etc. are the few example of CUMITHERM® application. CUMI has patent on a high-performance special designed Al2TiO5-tile lined launders products for non-ferrous cast-houses. The key benefits to the users are (a) longer service life, (b) energy efficiency, (c) increased process reliability, (d) down-time reduction for reduced maintenance and (e) high-quality of processed metals