Effects of Speeds, Materials, and Tool Rake Angles on Metallic Particle Emission During Orthogonal Cutting

Abstract

Dry high speed machining has been proposed as a viable and cost-effective process in metal cutting industries. However, it produces fine and ultra-fine metallic particles, also referred to as dust, which can be harmful to the machine-tool operator. The risk associated with exposure to metallic particles increases as the particle size decreases. For machining processes, little data exist on the size and distribution of dust generated during the shaping of materials. In order to reduce or eliminate the generation of these particles, it is necessary to understand how and under which conditions they are formed, as well as to be able to make predictions. In this study, the effects exerted by tool geometry, material, and machining parameters on dust emission were studied experimentally in order to understand the mechanisms of dust generation and to develop a predictive model. The particle sizes studied include the PM2.5 (particles with aerodynamique diameter below 2.5 lm) and a distribution of nanoparticles varying in size from 10 nm to 10 lm. Using dry machining and reducing the amount of dust generated should improve the air quality in machine shops in addition to helping protect the environment.

Modeling of Particle Emission During Dry Orthogonal Cutting

“…Experimental studies have shown that dry aerosols generated during metal machining depend on the workpiece material and its conditions, as well as on the cutting parameters (Ref 21,28,29) and the tool geometry (Ref 30,31) used.…”

“…To the authorsÕ knowledge, the literature contains only limited models for predicting particle emissions during machining processes (Ref 27,30,31). Zipf and Bieniawski (Ref 32) proposed a phenomenological interpretation for fine particle emission, but only during coal machining, thus making it inapplicable to metals.…”

“…For metallic particles generated during machining processes, cutting conditions (cutting speed, depth of cut, and feed rate), tool geometry (rake angle and lead angle), and workpiece material, have been found to be influential factors (Ref 30,31). They also have an impact on the cutting process itself, especially on the shearing of metal, on the friction, and on the plastic deformation.…”

“…While simple and very convenient, this model was, however, validated only on medium-density fiberboard materials. Further, it fails to recognize the behavior of ductile materials on particles emission, which presents a decreasing zone beyond a certain cutting speed (Ref 21,(27)(28)(29)(30)(31).…”

“…Recent experimental studies performed by Khettabi et al (Ref 30,31) showed the major effects of different cutting parameters, tool geometries, and workpiece materials on metallic particle generation during the machining of metallic materials. Zaghbani et al (Ref 27) proposed a semi-predictive model for fine metallic particle generation during high-speed milling using the energy created in the primary chip deformation zone and the measured cutting forces data.…”