Effect of various parameters on the black coring formation in ceramic tile
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Date
2019-05
Authors
Muhammad Azrin Bin Abd Jamil
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Abstract
In this research an attempt have been made to study the effect of various parameter on black core formation in ceramic. Sample were prepared based on parameter raw material (sawdust and iron oxide, Fe2O3), different pressing pressure for shaping (31.5, 33.25, 36.5 and 38.5 MPa), different particle size of powder (355, 425, 1000 µm) and firing condition (industrial furnace and laboratory furnace). All sample’s undergo wet milling and mixing for 3 minutes. The slip was then dried in oven (100 ºC, 24 hours), crushed and sieve (600 µm) into powder form. The powder was then fabricated using a uniaxial pressing (35 MPa) to form a 50 mm diameter test button and followed by drying in oven for 24 hour at 100 °C. Sample were then fired at industrial furnace at 1200 °C. Fired samples were characterized by, linear shrinkage, bulk density, water absorption, mechanical evaluation (modulus of rupture (MOR)), energy dispersive X-ray (EDX) for element composition, Scanning Electron Microscope (SEM) for microstructure examination and X-ray Diffraction (XRD) analysis for phase identification. All parameter show black coring formation except in firing condition parameter where sample fired at laboratory furnace show no black coring formation. Indicating firing condition play an integral part in the formation of black coring. However, in this study the addition of organic matter (sawdust) show the most severe black coring formation at 49% surface area. This is due to incomplete oxidation of organic matter (sawdust) forming carbon coke residue. The formation of black coring reduce the mechanical strength of fired sample where the MOR value for black coring sample are 30.30 N/mm2 compare to no black coring sample at 47.72 N/mm2 . This study proves organic matter (sawdust) is the main caused for the black coring formation.