Análise experimental do efeito das condições de corte no microfresamento do aço ferramenta AISI H13

Abstract

The micromilling process allows the manufacture of miniaturized parts and machining of micro details in different that meets strict quality requirements. Among the applications in the metalworking industry, the micromilling of tool steels for the manufacture of molds and dies stands out. However, micromilling applied to tool steels is a challenge due to the short tool life when machining these steels. Thus, the study of the influence or selection of cutting parameters on the micromilling process is of great importance to combine tool life and quality of the machined surface. Thus, the present work experimentally investigates the effect of different cutting conditions, with variation in feed rate (1 µm/tooth, 5 µm/tooth and 10 µm/tooth) and depth of cut (10 µm, 20 µm and 40 µm) in the machining of AISI H13 tool steel in the annealed condition during the micromilling process. For this purpose, 400 μm diameter carbide end micromills coated with (Al, Ti) N were used. The tests consisted of machining microchannels using a micromilling machine tool with a maximum spindle speed of 60 000 rpm. The wear of the microtools, surface roughness parameters Ra and Rq, burr formation and chips types were investigated. The wear of the microtools was evaluated by comparing images of new and worn tools obtained by scanning electron microscope (SEM). The machined microchannels were also observed in the SEM for visual analysis of the machined surface and the generated burrs. The results obtained for the Ra parameter ranged from 0.1310 to 0.1648 µm and the Rq values ranged from 0.1631 µm to 0.2254 µm. Machining under the highest feed of 10 µm /tooth, resulted in the lowest tool wear, whereas under the highest depth of cut, 40 µm, resulted in the lowest tool wear.