Vibration and stability in dry rough milling AZ31B magnesium alloy using end mills with different edge geometry

Abstract

Modern milling methods should ensure high quality and stability of machining processes. Increased manufacturing demands require the use of advanced machining methods. The aim is to use milling as both a preliminary (rough) and finishing operation, eliminating e.g. the grinding process. Vibrations generated during machining are an integral part of the process, however, they should be minimized. Therefore, the current research focuses on the vibrations analysis during magnesium alloy rough milling. This alloy is often used in various industries and the application and use of magnesium alloys is considered innovative. The main objective of the research was an assessment of vibration and stability during dry end milling processes and to study the influence of machining technological parameters and end mill geometry. The basis of the research carried out is the recording and analysis of the vibration acceleration signal in the time domain. In the research were used end mills with different edge geometry (different rake and helix angles). A frequency domain analysis of selected vibration signals was also performed (Fast Fourier Transform spectral analysis). Vibration acceleration parameters such as maximum, peak-to-peak value, root mean square and Composite Multiscale Entropy were also determined. It was noticed that for certain milling parameters, increasing the rake angle causes a greater degree of disturbance of the measured acceleration signal. In the vast majority of cases observed, the maximum does not exceed 1 m/s², which may indicate a very good stability of the implemented process, despite the use of effective, high values of machining parameters.