DEVELOPMENT OF AUTOMOTIVE BRAKE PAD FROM COMPOSITES OF SHEA NUT (VITELLARIA PARADOXA) SHELL AND COW HOOF (BAUHINIA UNGULATA)
ABSTRACT
This research work used shea nut (vitellaria paradoxa) shell and cow hoof (bauhinia ungulata) as the reinforcement materials in the production of automotive brake pads. Taguchi method of experimental design and grey relational analysis were used to determine the optimal values of the manufacturing parameters. Other constituents combined together to produce the brake pad samples were epoxy resin, graphite, calcium carbonate and aluminium oxide. The optimal values obtained for SNS-reinforced samples were moulding pressure (15MPa), moulding temperature (900C), moulding time (9mins) and post curing time (1hour) while the values for CH-reinforced samples were 13MPa, 900C, 11mins and 2hours respectively. The optimized samples for each reinforcement were produced and subjected to water absorption, oil absorption, compression, hardness, wear rate and coefficient of friction tests. Other examinations carried out were thermo-gravimetric analysis, thermal conductivity test and morphological structure analysis. The results of the tests obtained for SNS-reinforced sample are 0.0591%, 0.0661%, 88.5MPa, 42.5HV, 0.216mg/m and 0.7103 respectively while that of the CH-reinforced sample are 0.0739%, 0.105%, 84MPa, 43HV, 0.1972mg/m and 0.781 respectively. The thermo-gravimetric analysis showed that the SNS- reinforced sample was more stable thermally than the CH-reinforced sample. However, the two samples have their maximum decomposition at a higher temperature range of 3000C – 4000C which falls within the range of average brake temperature. Thermal conductivity test gave 0.02154Wm- 1K-1 and 0.0248 Wm-1K-1 for SNS-reinforced and CH-reinforced samples respectively. The morphological structure analysis showed that there was uniform distribution between the resin and the two reinforcement materials. These results obtained showed that SNS and CH are promising replacements for asbestos in automotive brake pad production.