An investigation of the wear behaviour of Ni3Al+B intermetallic compound of various temperature

ABSTRACT Master Thesis AN INVESTIGATION ON THE WEAR BEHAVIOUR OF Ni3Al+B INTERMETALIC COMPOUND AT VARIOUS TEMPERATURES Murat Yavuz SOLMAZ Fırat University Graduate School of Natural and Applied Sciences Department of Metallurgical and Materials Engineering 2002, Pages: 80 From the view point of abrasive wear, the effects of load, sliding speed and distance on the weight loss of Nİ3AI intermetallic alloys were investigated for various temperatures, 25, 100, 300 and 450°C. SEM, EDS and XRD analysis were performed to identify the worn surfaces to explain the wear mechanisms. In the first and second chapters of this study, structures and mechanical properties of Nİ3AI intermetallic alloys were presented and literature about this topic were reviewed. In the third chapter, wear and wear affecting factors were presented. In the fourth chapter, experimental studies collected from the literature on the abrasive wear of intermetalic-based alloys and composites were presented. In the fifth chapter, experimental procedures were given. And, results and discussion were presented in the sixth chapter. Finally, in the seventh chapter, conclusions and suggestions for the future studies were presented. During the wear experiments; oxidation, mass transfer from counturface material to the test material and plastic deformation occurred on the wear surface were appeared as important factors on the weight loss mechanisms.VI The weight loss values of wear tests in the room temperature gave similar results in all experiment in terms of loading, sliding speed and distance parameters. Increase in values of these parameters resulted more weight loss. In 100°C, the weight loss for various loading, sliding speed and distance parameters are higher about 10-15 times than weight loss values in the experiments done in the room temperature. The plastic deformation on the test material surface occurred at the low temperature, and much more oxide layer formed at the higher temperature than that of 100°C and these factors mainly affected the wear results. The weight loss reached to the maximum values at 100°C. Because, both of these mechanisms in this temperature are less effective than mechanisms in the other temperatures. The weight loss for wear experiments performed at 300 and 450°C gave similar results for all loadings, sliding speeds and distance parameters. Wear progressed by two mechanisms when the temperature was increased to 450°C. In the first mechanism, oxide layers occurred on the wear surfaces with increasing temperature; in the second mechanism, some particles transferred from counterface surface to the main material. The types and densities of oxides occurred during the wear tests on the sliding surfaces increased with increasing temperatures and parallelly the mass values transferred from counterface material to major test material increased. Therefore, the weight loss values at the high temperature are less than at the lower temperatures. Keywords : Intermetallic Compound, Nİ3AI, Wear, High Temperature.