Minimum quantity lubrication (MQL) is an alternative over dry machining due to economic and ecological sustainability. In the current research, a comparative investigation has been carried out on machinability and surface integrity aspects of hardened AISI 4340 steel using PVD TiAlN coated carbide inserts during dry and MQL assisted hard turning. Under the dry condition, turned surface has been encountered tensile residual stress whereas compressive residual stress has been generated under MQL condition. Formation of a white layer on the chip has not been experienced under both conditions. Cutting speed predominantly influences tool wear and feed influences more on surface roughness. Dimensional deviation and auxiliary flank wear have been significantly reduced under MQL condition with 16.21% cost savings. An improvement in machinability characteristics and surface integrity under MQL cutting has been noticed compared to dry with favorable interaction and contribute towards cleaner machining process. This may be adopted in machining shop floor as a good replacement over dry machining.

中文翻译：

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使用PVD TiAlN涂层硬质合金刀片的MQL辅助清洁机加工：比较评估

由于经济和生态上的可持续性，最小量润滑（MQL）是干式加工的替代方法。在当前的研究中，已经在干燥和MQL辅助硬车削过程中使用PVD TiAlN涂层硬质合金刀片对AISI 4340硬化钢的可加工性和表面完整性方面进行了比较研究。在干燥条件下，车削表面会遇到拉伸残余应力，而在MQL条件下会产生压缩残余应力。在两种情况下都没有经历芯片上白色层的形成。切削速度主要影响刀具的磨损，进给对表面粗糙度的影响更大。在MQL条件下，尺寸偏差和辅助齿面磨损已大大降低，节省了16.21％的成本。与具有良好相互作用的干燥相比，已经注意到在MQL切削下可加工性和表面完整性得到改善，并有助于更清洁的加工过程。这可以在加工车间中采用，以替代干式加工。