A influência da nitretação a plasma e da utilização de fluido de corte na análise de desgaste de brocas de aço rápido (HSS)

Abstract

Cutting tool wear is a recurring problem within the metalworking industry, and this problem can be reduced but cannot be eliminated. In this context, it is of great importance the study of new materials, processes and wear mechanisms aspiring to the performance they can have in service. With this in mind, plasma nitriding has significant results in some mechanical properties such as increased microhardness and wear resistance. Just as the application of cutting fluids during machining processes also yields excellent results in extending tool life. From this, this work aims to evaluate the application of plasma nitriding (at temperatures of 400 ° C and 450 ° C) and the use of cutting fluid in the drilling process of SAE 5160 steel with high speed steel drill bits - HSS and cobalt fast steel drills - HSS-Co. For this work, the characterization of the drills was performed by Vickers Microhardness test, Optical microscopy and performance test, where the flank wear on the cutting edge was measured. Thermochemical treatments resulted in the elevation of the surface hardness of the drills compared to the initial state. Optical microscopy proved that plasma nitriding effectively performed nitride layer deposition on the drills, however, because the layers formed are very thick, this negatively influenced their design. Performance analysis revealed that the HSS-Co cobalt-fast drill with the application of cutting fluid achieved the best performance in the drilling process, proving that application of fluid can increase productivity when compared to the dry process.