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Clean machining is gaining ground as one of the crucial issues in future manufacturing. Many machining industries are looking for alternative solutions to wet machining because of the costs of the latter, including environmental costs, as well as its impact on occupational health and safety. Dry machining is being proposed, but in most conditions, the cutting tool wears out quicker, leading to part quality deterioration and increased machining costs. Minimum quantity lubrication (MQL) machining is also proposed to maintain a reasonable tool life and limited cost, as compared to the situation with flood or wet machining. Both the MQL and dry machining methods, however, are susceptible to the generation of aerosols containing metallic particles that can be detrimental to occupational health and safety. Minimizing particle emissions is of prime importance since these can have serious consequences on the operator's health. They have been seen to be at a minimum at two specific cutting ranges. In this study, investigations are done to examine the effect of lubrication (dry and MQL) during the turning of the 7075-T6 aluminum alloy. The performance indexes studied are the surface roughness, the chip thickness, and aerosol generation. [ABSTRACT FROM AUTHOR]

Sustainable manufacturing regulations are pushing manufacturing towards decreasing of manufacturing hazards including microparticles and ultrafine particles. Machining process such as milling produces dust that can be harmful for operators' health. The emission of this dust depends on workpiece materials (microstructure, mechanical properties) and machining conditions. The aim of this paper is to determine the effect of the microstructure and machining conditions on dust emission during dry milling of Al-20Mg2Si-2Cu metal matrix composite with addition of bismuth (Bi) and barium (Ba). Experiments were carried out using dry CNC milling by uncoated carbide tools. An aerodynamic particle sizer (APS) and a scanning mobility particle sizer (SMPS) were used to measure microparticles and ultrafine particles emission, respectively. It was found that the addition of 0.4 wt% Bi and 0.2 wt% Ba changed Mg2Si particle size and improved the hardness of composite. In addition, ultrafine particle number concentration, specific area concentration and mass concentration decreased with the addition of modifiers. It is also confirmed that cutting conditions and microstructure of workpieces have a direct effect on dust emission during the milling process. [ABSTRACT FROM AUTHOR]