Development of electrical porcelain insulators from ceramic minerals in Uganda
2014 (English)In: Ceramic Engineering and Science Proceedings, 2014, no 2, 115-125 p.Conference paper (Refereed)
Characterisation studies on ceramic minerals in Uganda have revealed their possibility for application in ceramic insulator production. Sand, feldspar and clay were used to formulate porcelain bodies based on established theories for ensuring high dielectric and mechanical strength. Sintering profiles and their effects on strength, crystalline phase content and morphology were investigated using dilatometiy, 4-point bending strength, XRD and FEG-SEM. Optimum properties of insulators from these minerals were attained with heating/cooling rates of 6°C/min to peak temperature of 1250°C with dwell time of 2h. The quartz content of the sintered body decreased as peak temperature was increased beyond 1250°C along with a decline in strength of the bodies. Neither increasing dwell time at 1250°C nor reducing the heating/cooling rate to less than 6°C/min for a peak temperature of 1250°C were shown to result in improvement of strength. The morphology of mullite crystals did not change with change in either heating/cooling rate or dwell time at peak temperature of 1250°C. The industrial sized specimens produced exhibited dry and wet flashover voltages of 22.8kV and 11.4kV respectively, transverse load capacity of 12.5kN and bulk density of 2.27g/cm3. These are satisfactory for low voltage insulation applications.
Place, publisher, year, edition, pages
2014. no 2, 115-125 p.
Clay, Flashover, Mechanical properties, Morphology, Porcelain, Quartz, Silicate minerals, Sintering, Ceramic insulators, Crystalline phase, Heating/cooling rate, High dielectrics, Mullite crystals, Optimum properties, Peak temperatures, Porcelain insulators, Bending strength
IdentifiersURN: urn:nbn:se:kth:diva-167889ISI: 000361040200012ScopusID: 2-s2.0-84916216656OAI: oai:DiVA.org:kth-167889DiVA: diva2:820867
Mechanical Properties and Performance of Engineering Ceramics and Composites IX - 38th International Conference on Advanced Ceramics and Composites, ICACC 2014, 26 January 2014 through 31 January 2014
QC 201506122015-06-122015-05-222015-10-08Bibliographically approved