EFFECTS OF FLY ASH ADDITIVE ON THE PROPERTIES OF RAILWAY COMPOSITE DISC BRAKE LININGS

Brake friction materials should satisfy a number of requirements such as stable friction coefficient, low wear rate, environmentally friendly, lightweight, long life, low noise, corrosion resistance and acceptable cost versus performance characteristics. Fly ash is an important side product, which accumulates in cyclone or electro filters through chimney gases occurring as a result of the combustion of pulverized coal in thermal power plants. In Turkey, approximately 45 million tons of coal is combusted annually and an average of 15 million tons of fly ash is produced. World annual production of fly ash is about 600 million tons. Fly ash which results from the coal-operated power plants causes economic and environmental problems. Fly ash particles are suitable for using in the brake linings of railway as a filler material. Waste fly ashes which contain compositions of Al2O3, SiO2, Fe2O3 from thermal power plants are used as brake lining. Many studies have been undertaken to show that adding the environmentally harmful waste to lining material could be used in a cost reducing way. In this study, the fly ash obtained from coal-fired thermal power plant “Orhaneli and Kemerköy” was used. Our recent study has focused on development and utilization of fly ash for railway frictional composites. Produced composites brake linings contain 40% fly ash in weight ratio from Kemerköy and Orhaneli. We compared the frictional and wear behavior of fly ash reinforced composite brake linings are compared on a commercial railway disk brake lining. The new developed brake linings have exhibited consistent properties; density of 1,79-2,18 g/cm3, hardness of 107-112 Hardness Rockwell L (HRL), modulus of elasticity in compression of 376-448 MPa, internal shear strength 15-46 MPa, and coefficient of friction 0,353-0,417.

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  • [1] E. Akagündüz, M. Güneş, Z. Yücel, “Brakes- The Most Significant Invention after the Engine”, Railway Turkey Suppliers Magazine, 2, 47-53, 2013.
  • [2] S. Mohanty, Y.P. Chugh, “Development of Fly Ash-Based Automotive Brake Lining”, Tribology International 40, 1217–1224, 2007.
  • [3] M. Eriksson, “Friction and Contact Phenomena of Disc Brakes Related to Squeal. Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology”, ACTA Universitatis Upsaliensis, 537, 8-44, 2000.
  • [4] R.S. Blissett, N.A. Rowson, “A Review of the Multi Component Utilisation of Coal Fly Ash”, Fuel , 97, 1–23, 2012.
  • [5] V.M. Malhotra, P.S. Valimbe, M.A. Wright, “Effects of Fy Ash and Bottom Ash on The Frictional Behavior of Composites”, Fuel 81, 235–244, 2002.
  • [6] B.K. Satapathy, A. Majumdar, B.S. Tomar, “Optimal Design of Flyash Filled Composite Friction Materials Using Combined Analytical Hierarchy Process And Technique For Order Preference By Similarity To Ideal Solutions Approach”, Materials and Design 31,1933-1944, 2010.
  • [7] N. Dadkar, B.S. Tomar, B.K. Satapathy, “Evaluation of flyash-filled and aramid fibre reinforced hybrid polymer matrix composites (PMC) for friction braking applications”, Materials And Design, 30, 4369-4376, 2009.
  • [8] K.W. Hee, P. Filip, “Performance of ceramic enhanced phenolic matrix brake lining materials for automotive brake linings”, Wear 259, 1088-1096, 2005.
  • [9] N. Dadkar, B.S. Tomar, Satapathy B.K., A. Patnaik, “Performance Assessment of Hybrid Composite Friction Materials Based on Fly Ash-Rock Fibre Combination”, Materials and Design 31, 723-731, 2010.
  • [10] B.K. Satapathy, A. Patnaik, N. Dadkar, D.K. Kolluri, B.S. Tomar, “Influence of Vermiculite On Performance of Flyash-Based Fibre-Reinforced Hybrid Composites As Friction Materials”, Materials and Design, 4354-4361, 2011.
  • [11] B.K. Satapathy, A. Majumdar, H.S. Jaggi, A. Patnaik, B.S. Tomar, “Targeted Material Design of Fly Ash Filled Composites For Friction Braking Application By Non-Linear Regression Optimization Technique”, Computational Materials Science, 3145-3152, 2011.
  • [12] M. Kumar, B.K. Satapathy, A. Patnaik, D.K. Kolluri, B.S. Tomar, “Hybrid Composite Friction Materials Reinforced With Combination of Potassium Titanate Whiskers and Aramid Fibre Assessment of Fade And Recovery Performance” Tribology International, 359-367, 2011.
  • [13] Blau, P. J. “Compositions, Functions, And Testing of Friction Brake Materials and Their Additives”, August 2001
  • [14] SAE Recommended Practice-SAE J866, Friction Coefficient Identification System for Brake Linings, 2012.