The Influence of Sintering Temperatures on the Mechanical Properties of Glass Ceramics Made from Coal Fly Ash and Glass Waste
1Postgraduate student in Mechanical and Industrial Engineering, Gadjah Mada University
2Department of Mechanical and Industrial Engineering, Gadjah Mada University
3Department of Physical Engineering, Gadjah Mada University, Faculty of Engineering, Gadjah Mada University, Jl. Grafika No. 2 Yogyakarta - 55 281 (Indonesia).
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In this study, glass ceramics composites made from the mixture between fly ash and glass waste powder. The glass waste powder was varied 0%, 10%, 20%, 30%, and 50%. Each mixture was uni-axially pressed using stainless steel molding with a compacting pressures of 130 MPa to produce green body. The green body was then sintered using pressure less sintering method with a heating rate of 5?C/min at various temperatures of 900, 950, 1000, 1050 and 1100?C for 2h. From the experimental result, it shows that the increase of glass waste powder contents in the composites tends to increase mechanical properties of glass ceramics product. The optimum properties of glass ceramics in this study were obtained from specimen with mixture ratio of 50% fly ash + 50% glass waste with compacting pressure of 130 MPa. The maximum hardness of 2205 MPa and density of 2.03 g/cm? is obtained in the 50FA-50GL specimen with sintering temperature of 1100?C while the maximum bending strength of 45 MPa is obtained in the specimen with sintering temperature of 1050?C. The presence of crystalline phases in the glass ceramic specimen is highly varied based on the composition of green body before sinter. The major crystalline phases are found in the glass ceramics specimen corresponds to quartz (SiO2), mullite syn. (Al4.64Si1.36O9.68), Hematite (Fe2O3), Albite Ca-rich [(Na,Ca)Al(Si,Al)3O8], MAPO-20 syn. (C8H24Al4Mg2N2O24P6), and enstatite (Mg1.83Fe0.17Si2O6).
KEYWORDS:fly ash; glass ceramic; sintering; mechanical properties; waste
Accepted on: 25 Sep 2008
