Investigating the Surface Roughness of Hardened Tool Steel (2379) during Face Milling Operation

Hard milling is considered to be a precise and efficient machining method for the die and mold manufacturing industry. The main criterion for evaluating the cutting processes of the parts designed for these applications is the quality of the machined surfaces. For this reason, the analysis of the factors that influence the surface roughness obtained in this processes is important for helping the process become more productive and competitive. The present paper presents some results and an empirical model for surface roughness when high speeds face milling of AISI W1 tool steel. The influence of cutting parameters and material hardness is investigated by using Taguchi design of experiments. The results obtained show that high speed face milling of hardened tool steel AISI W1 can be carried out in economical conditions(on plant milling machines) and can lead to satisfactory surface quality (Ra =0.2-0.36 μm).

Surface flatness and roughness has a pivotal role in the functioning of any kind of check valve. These two parameters are mainly obtained by face milling[16] during the manufacturing process of valves. The values of these affect during leakage rejection and redesign of check valves. To achieve the desired values of surface flatness and roughness here analysis is carried out. A regression model is generated to predict the values of surface roughness and flatness. ANOVA is also developed to see the effect of machining process parameters on the surface roughness and flatness.

The grinding process is a machining process to obtain qualified surface roughness levels and high dimensional accuracy. There are two types of processes in the grinding process, namely the roughening and finishing processes. The vibration effect of the roughing process can damage and shorten the life of the tool/machine, while in the finishing process, the effect of vibration will reduce the dimensional accuracy, shape, and surface smoothness of the workpiece. This study aims to determine the effect of crossfeed on the amplitude of vibration and surface roughness of the workpiece on the surface grinding process. The materials used are hardened tool steel OCR12VM with a variety of grinding stone types A46QV and A80LV made of aluminum oxide. The Variables of process parameters are crossfeed (mm / step) and depth of cut (mm). The measurement of vibrations uses an accelerometer, which is processed by the math CAD program in the form of amplitude and frequency. For surface roughness measurements, it is used the MT-301 surface test with 5 sample points and a sample length of 0.8 mm. The results show that the greater the cross-feed value, the bigger the amplitude of the vibration level and the surface roughness of the workpiece. The magnitude of the amplitude of the vibration on the acceleration that occurs in the grinding stone type A46QV starts from 6,7369 -18.7525 g.rms, while the grinding stone type A80LV starts from 5.0904 g.rms to 18.2821 g.rms. The surface roughness achieved in both grit 46 and grit 80 is from N3 to N5.

The development of industry in the last ten years has caused the production of parts with relatively small dimensions. This has led to intensive development of efficient micro-technologies through research of processes, machines and tools. This paper presents the research of machinability, channels micro-milling in AISI D2 tool steel (X155CrVMo-5), hardened to 62 HRc. As the tool is used micro-milling cutter with diameter of 0.6 mm and relatively large working length of 5 mm. Analysis of surface roughness, burr on workpiece edges and reduction of cutter diameter due tool wear was performed.