Characterization and comparative machinability investigation of extruded and drawn copper alloys using non-parametric multi-response optimization and orthogonal arrays

摘要

The aim of this paper is to identify the observed differences during machining in terms of microstructure-property relationship, as well as to determine the optimum cutting conditions, using non-parametric design of experiments methods applied in turning processes of special leaded brass bars used in industrial applications. For this purpose, industrial copper alloy rods, namely CuZn39Pb3 (CW6l4N - Brass 583) and CuZn36Pb2As (CW602N - Brass DZR) for machining applications, were investigated as far as their microstructure and mechanical behaviour are concerned, including lead particle distribution and phase structure characterization, hardness, tensile and impact properties. Machinability was assessed qualitatively and quantitatively by evaluating the chip size and morphology and the corresponding cutting tool wear land, employing the appropriate single point turning technique. Optical and scanning electron microscopy, hardness, tensile and impact testing were used as the major analytical techniques in the context of the present investigation. Moreover, a multi-nonparametric study employing design of experiments was properly implemented in order to identify the critical-to-machinability parameters and to obtain their optimum values for high-performance production. It was found that solely the alloy Brass 583 was influential in chip morphology while the concurrent optimization with cutting tool wear only introduced excessive variation in the scheme that overall phased out any dependencies.