Production of ceramics reinforced bronze based powder metal breake linings and investigation of their friction-wear behaviours

Ill PRODUCTION OF CERAMICS REINFORCED BRONZE BASED POWDER METAL BREAKE LININGS AND INVESTIGATION OF THEIR FRICTION- WEAR BEHAVIOURS ( Ph.D. THESIS) Mustafa BOZ GAZI UNIVERSITY INSTUTE OF SCIENCE AND TECHNOLOGY DECEMBER 2003 ABSTRACT This study consisted of two stages: In the first stage, bronze based break linings were produced and friction-wear properties of them were investigated. In the second stage, various amount of ceramics powder (SİO2, AI2O3, Mg8Sii203o(OH)4(OH2)4 8H20, Sb2S3 ve ZrSi04) were added to bronze-based powders and ceramics reinforced bronze-based break lining were produced. Friction-wear properties of the ceramics reinforced samples were measured and compared to those of plain bronze based ones. For this purpose, density, hardness, friction coefficient and wear behaviour of the samples were tested. Microstructure of samples before and after sintering and also worn surfaces were investigated by using a scanning electron microscopy (SEM) and the wear type were determined. At the end of experimental study, the optimum friction-wear behaviour was observed on the sample compacted at 350 MPa and sintered at 820°C. With increasing the amount reinforcing elements (except ZrSi04) resulted in aIV decrease in density of the final samples. The most dense break-lining materials was obtained on the sample reinforced with ZrSi04. All samples exhibited friction-wear values which were within the values shown in SAE-J661 standard. However samples reinforced with 5% ZrSi04 and 6% ZrSiC>4 gave best results. Science Code : 710 Key Words : Powder Metallurgy, Brake Lining, Friction-Wear and Ceramics Page Number : 130 Adviser : Assoc. Dr. Adem KURT