Estudo sobre a utilização do rejeito de granito rosa Iracema como matéria-prima para a fabricação de funis de saída da fiação a rotor da indústria têxtil. Parte I : caracterização do material

Abstract

The spinning navel is a component widely used in the textile industry. Such navels are basicaly alumina or high-alumina ceramic parts, and since they are not produced in Brazil, they are imported at high costs. For this reason, an alternative material for the fabricationof hte navel was proposed, consisting of granite powders.Since granites are basically silicates and exhibit lower mechanical strength and hardness when compared to aluminas, a reinforcement of submicrometric alumina particles was introduced. In this way , properties similar to those from commercial navels were obtained. This work reports studies on the characterisation of both the proposed composite material and materials from two different types of navels. Fragments from these navels as well as a sample from Rosa Iracema granite powder were analysed. X-ray difration and X-ray fluorescence .Specific surface area was determined for the granite powder and for the alumina particles.Thermogravimetric analysis of the pure granite powder and of mixtures of granite powder and alumina particles was also made. Disk samples of mixtures of granite powder and alumina particles containing 5, 10, 20, 30, 40, 50, 60, 70, 80, 90 wt% alumina were compression molded and sintered at 1200ºC and mixtures containing 30, 40, 50, 60, 70, 80 and 90 wt% alumina were sintered at 1500ºC. The sintered bodies were studied by SEM and EDS. From these preliminary studies further investigative work was undertaken in order to find a compromise between cost and quality of the finished part compared to the imported navels. The emphasis of the research was on the development of a composite with a granite (silicaceous) matrix reinforced with alumina particles that would exhibit properties as closeas possible to those exhibited by the imported parts.