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 II: propriedades físicas

Abstract

In this work, physical properties of sintered compacts made from granite powder reinforced with alumina particles were determined. This composite is proposed as an economic alternative to the more expensive pure alumina, currently used in the fabrication of spinning navels for the textile industry. The composite material was compared to the materials from some spinning navels currently in use in a textile plant. The test pieces were obtained by compression molding of mixtures of granite powder and different amounts of alumina particles sintered at 1200ºC and 1500ºC. Since the sintered body has to fulfill the requirements for thread production (strength, hardness and surface finishing), these characteristics were evaluated by Vickers microhardness, diametral compression( Brazilian test) and roughness analysis, respectively. Only the hardest samples had their surface analysed. Samples taken from commercially available navels were also tested. Dimension control of samples sintered at different temperatures was performed. The gresification curve was determined for the composites sintered at 1200ºC and 1500ºC. This curve is built using results from water absorption and linear retraction. Samples of Rosa Iracema granite (matrix) containing 30 and 40 wt% of submicrometric alumina sintered at 1500º C presented results comparable to those from imported spinning navels made from more expensive materials. Such results show the feasibility of the use of the proposed composite, but also the need to further research on the subject .