Due to rising attention towards environmental and ecological issues caused by mineral oil-based lubricants in machining operations, the developing of an environmental favourable lubricant has become inevitable. As environmental favourable cutting fluids, vegetable oils have acquired great attention in machining operations due to their good biodegradability, non-toxicity and less environmental pollutant properties. Nowadays, the minimum quantity lubrication (MQL) technique is explored as alternative technique to conventional flood cooling technique. However, very limited work is done to investigate the effect of MQL technique using vegetable oils as the base oil for machining of hard materials. Moreover, systematic comparison of different vegetable oils as the base oil will be of great significance to the manufacturing industry. Therefore, in this study, the performance of six vegetable oils viz. castor, coconut, soybean, canola, palm and sunflower oil, and distilled water has been investigated during drilling of stainless steel (AISI 321) using minimum quantity lubrication technology. The main objective of this study is to compare the performance of various cooling strategies viz. dry, flood and seven MQL conditions with respect to drilling characteristics (thrust force, torque, surface roughness, coefficient of friction (COF), chip morphology and wear mechanism) in the drilling of stainless steel (AISI 321) by using HSS drill tools. Experimental findings showed that MQL drilling conditions have given excellent drilling performance by improving drilling characteristics than dry and flood drilling. Among the MQL fluids, sunflower oil provided better lubrication and improved the drilling characteristics followed by palm, canola, soybean, coconut, castor oil and distilled water. Sunflower oil had a thrust force, torque, surface roughness and coefficient of friction of 1425 N, 22.8 Nm, 4.356 µm and 4.000 µ, which reduced by 21.27%, 25.49%, 30.72% and 5.35%, respectively than that under flood drilling at 30th hole. The better lubrication performance of sunflower oil may be attributed to the rich presence of saturated-fatty acids. In addition, vegetable oils based MQL technique is more worthy to improve the cooling capabilities and promote sustainability in the manufacturing sector by saving resources and extending environmental benefits.

由于在加工操作中对由矿物油基润滑剂引起的环境和生态问题的关注日益增加，开发对环境有利的润滑剂已成为必然。作为对环境有利的切削液，植物油由于其良好的生物降解性，无毒性和较少的环境污染物特性而在机加工操作中引起了极大的关注。如今，探索了最小量润滑（MQL）技术作为常规洪水冷却技术的替代技术。但是，为研究使用植物油作为基础油来加工硬质材料的MQL技术的效果，所做的工作非常有限。此外，系统比较不同的植物油作为基础油对制造业也将具有重要意义。所以，在这项研究中，六种植物油的性能即。脚轮，椰子，大豆，低芥酸菜子，棕榈和葵花籽油以及蒸馏水已在不锈钢（AISI 321）钻孔过程中使用最小量润滑技术进行了研究。这项研究的主要目的是比较各种冷却策略的性能。在使用HSS钻孔工具进行不锈钢钻孔（AISI 321）时，应考虑到干燥，溢流和七个MQL条件，这些条件涉及钻孔特性（推力，扭矩，表面粗糙度，摩擦系数（COF），切屑形态和磨损机理）。实验结果表明，MQL钻探条件通过改进钻探特性而比干钻和洪水钻探具有出色的钻探性能。在MQL流体中，葵花籽油提供了更好的润滑并改善了钻井特性，随后是棕榈，低芥酸菜籽，大豆，椰子，蓖麻油和蒸馏水。葵花籽油的推力，扭矩，表面粗糙度和摩擦系数分别为1425 N，22.8 Nm，4.356 µm和4.000 µ，分别比洪水钻削时的21.27％，25.49％，30.72％和5.35％降低。第30洞。葵花籽油更好的润滑性能可能归因于饱和脂肪酸的丰富存在。此外，基于植物油的MQL技术更值得通过节省资源和扩展环境效益来提高冷却能力并促进制造业的可持续性。扭矩，表面粗糙度和摩擦系数分别为1425 N，22.8 Nm，4.356 µm和4.000 µ，分别比第30孔的泛洪钻进降低了21.27％，25.49％，30.72％和5.35％。葵花籽油更好的润滑性能可能归因于饱和脂肪酸的丰富存在。此外，基于植物油的MQL技术更值得通过节省资源和扩展环境效益来提高冷却能力并促进制造业的可持续性。扭矩，表面粗糙度和摩擦系数分别为1425 N，22.8 Nm，4.356 µm和4.000 µ，分别比第30孔的泛洪钻进降低了21.27％，25.49％，30.72％和5.35％。葵花籽油更好的润滑性能可能归因于饱和脂肪酸的丰富存在。此外，基于植物油的MQL技术更值得通过节省资源和扩展环境效益来提高冷却能力并促进制造业的可持续性。