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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]

This article presents the influence of machining conditions on typical process performance indicators, namely cutting force, specific cutting energy, cutting temperature, tool wear, and fine dust emission during dry milling of CFRPs. The main goal is to determine the machining process window for obtaining quality parts with acceptable tool performance and limited dust emission. For achieving this, the cutting temperature was examined using analytical and empirical models, and systematic cutting experiments were conducted to assess the reliability of the theoretical predictions. A full factorial design was used for the experimental design. The experiments were conducted on a CNC milling machine with cutting speeds of 10,000, 15,000, and 20,000 rpm and feed rates of 2, 4, and 6 µm/tooth. Based on the results, it was ascertained that spindle speed significantly affects the cutting temperature and fine particle emission while cutting force, specific cutting energy, and tool wear are influenced by the feed rate. The optimal conditions for cutting force and tool wear were observed at a cutting speed of 10,000 rpm. The cutting temperature did not exceed the glass transition temperature for the cutting speeds tested and feed rates used. The fine particles emitted ranged from 0.5 to 10 µm aerodynamic diameters with a maximum concentration of 2776.6 particles for those of 0.5 µm diameters. Finally, results of the experimental optimization are presented, and the model is validated. The results obtained may be used to better understand specific phenomena associated with the milling of CFRPs and provide the means to select effective milling parameters to improve the technology and economics of the process. [ABSTRACT FROM AUTHOR]

In the present study, an attempt has been carried out to investigate the effect of cutting fluid applications including dry, mist and flood drilling on the part quality during drilling of 6061-T6 aluminum alloy. The part quality criteria include the surface finish and burr size. A multi-factorial experimental design (DOE) and analysis was used. It has also been found that dry machining and mist machining can produce parts with quality comparable to those obtained in wet machining when using the optimal cutting conditions. [ABSTRACT FROM AUTHOR]