Laser-assisted micromilling is a promising micromachining process for difficult-to-cut materials. Laser-assisted micromilling uses a laser to thermally soften the workpiece in front of the cutting tool, thereby lowering the cutting forces, improving the dimensional accuracy, and reducing the tool wear. Thermal softening, however, causes the workpiece material to adhere to the tool and form a built-up edge. To mitigate this problem and to enhance micromachinability of the workpiece in laser-assisted micromilling, this article investigates the following lubrication and cooling methods: (1) minimum quantity lubrication and (2) vortex tube cooling. Experiments utilizing the two methods are carried out on a difficult-to-cut stainless steel (A286), and the surface morphology, tool condition, burr formation, groove dimensional accuracy, surface finish, and cutting forces are analyzed. Results show that the combination of laser-assisted micromilling and minimum quantity lubrication yields the least amount of tool wear, lower resultant force, better groove dimensional accuracy, and no built-up edge. While vortex tube cooling with laser-assisted micromilling produces smaller burrs compared to minimum quantity lubrication, it yields larger changes in groove dimensions and is characterized by built-up edge formation. Possible physical explanations for the experimental observations are given.

中文翻译：

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微量润滑和涡流管冷却对难切削钢激光辅助微铣削的影响

激光辅助微铣削是一种很有前途的难切削材料微加工工艺。激光辅助微铣削利用激光对刀具前方的工件进行热软化，从而降低切削力，提高尺寸精度，减少刀具磨损。然而，热软化会导致工件材料粘附在刀具上并形成积屑瘤。为了缓解这个问题并提高激光辅助微铣削工件的微加工性，本文研究了以下润滑和冷却方法：（1）最小量润滑和（2）涡流管冷却。用两种方法在难切削不锈钢（A286）上进行了实验，对表面形貌、刀具状态、毛刺形成、凹槽尺寸精度、表面光洁度、并分析切削力。结果表明，激光辅助微铣削和最少量润滑的组合产生最少的刀具磨损、较低的合力、更好的凹槽尺寸精度和无积屑瘤。虽然与最小量润滑相比，使用激光辅助微铣削的涡流管冷却会产生更小的毛刺，但它会产生更大的凹槽尺寸变化，并且具有积屑瘤形成的特点。给出了实验观察的可能物理解释。虽然与最小量润滑相比，使用激光辅助微铣削的涡流管冷却会产生更小的毛刺，但它会产生更大的凹槽尺寸变化，并且具有积屑瘤形成的特点。给出了实验观察的可能物理解释。虽然与最小量润滑相比，使用激光辅助微铣削的涡流管冷却会产生更小的毛刺，但它会产生更大的凹槽尺寸变化，并且具有积屑瘤形成的特点。给出了实验观察的可能物理解释。