Produção e caracterização de um compósito de matriz de aço inox AISI 304 com reforço de pó de alumina

Abstract

Manufacturing processes in the machining area have direct or indirect participation in all industrial sectors today, which causes an accumulation of large quantities of solid waste in the form of chips. Based on this, this work aims to obtain a metallic composite by reusing AISI 304 stainless steel chips from machining, in the form of powder ground by high energy grinding (MAE) and associated with alumina (Al2O3) as particulate reinforcement and scattered. The metallic composite was processed using three sample formulations, with values of 5, 10 and 15% by weight of alumina. After the uniaxial compaction process, the green samples were sintered at a temperature of 1150 °C at a rate of 10 °C/min. To characterize the composite material, the samples were subjected to analysis of apparent density, percentage porosity, three-point bending test, Vickers microhardness, Rockwell hardness and microstructural analysis using optical microscopy (OM) and scanning electron microscopy (SEM). From the values obtained through the characterization, an evolution was observed in the mechanical properties of the composite related to the gradual increase in the alumina content, from 5 to 15% by weight, presenting a significant drop in the percentage of porosity, greater apparent density and increased of hardness. For the 15% reinforcement formulation, a point hardness of 968HV was observed, a very promising characteristic when compared to the hardness values attributed to high-speed steels, which have a hardness between 700 and 940HV.