Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
INVESTIGATION OF SURFACE ROUGHNESS GENERATED BY END MILLING OF TOOLOX 44 ®
Submission Author:
Michele Ribeiro , RS
Co-Authors:
Michele Ribeiro, Heraldo José Amorim, André João de Souza
Presenter: Michele Ribeiro
doi://10.26678/ABCM.COBEM2021.COB2021-0118
Abstract
Toolox 44 ® is a highly engineered quench and tempered pre-hardened steel with high purity, low carbon content, high toughness, high yield strength at elevated temperature, and very low residual stress. Due to its characteristics, this material is suitable for situations where high hardness, high impact resistance, and excellent dimensional stability are essential such as plastic, rubber, die casting, bending, and sheet forming tools. Despite its good mechanical properties, it is reported to present good machinability. However, the cutting parameters must be carefully selected due to dynamic instability during machining this material. Also, the temperature control in the cutting zone is critical because it cannot be heated above 590°C. In this work, the machined surface finish is evaluated after dry and flood end milling of Toolox 44® with different cutting conditions. The 3-factor 3-level Box-Behnken design of experiments (BBD) was carried out to evaluate the influence of each controllable factor (cutting speed “v c ”, feed per tooth “f z ”, axial depth of cut “a p ”) and its combinations on the response variables (average surface roughness “R a ” and average maximum height of the profile “R z ”) for both lubricooling conditions. Through the BBD, it is possible to obtain the optimal levels of the input factors in terms of surface finish (lowest R a and R z values). In addition to the roughness parameters analysis, the roughness profiles corresponding to the lowest roughness values will also be evaluated. It is expected yet that the high v c combined with low f z and low a p results in lower R a and R z values when end milling Toolox 44 ® . Furthermore, lower roughness values can be obtained with wet milling compared to dry milling since the latter has the drawback of generating high temperatures in the cutting zone, culminating in a poor surface finish. Besides, significant influences of fz on the roughness profiles are expected due to the geometric contribution of the cutting tool. Also, high a p values can provide instabilities that significantly affect the machined surface finish.
Keywords
Toolox 44 ®, Box-Behnken Design, End milling, surface roughness
