Abstract

The present work aims to investigate the synergetic effect of titanium dioxide (TiO₂₎ and graphene (GnP) nanoparticle additives on the rheological and machining characteristics of biodegradable vegetable oil (rice bran). The rice bran oil has been used in turning of M2 steel using a minimum quantity lubrication (MQL) technique. The effects of varying concentrations by weight (0.5 and 1 wt%) of both mono (rice bran oil/TiO₂) and hybrid (rice bran oil/TiO₂/graphene) nanofluids have been studied. The rheological studies of both mono and hybrid oils revealed an improvement in the viscosity with an increase in nanoparticle concentration. Furthermore, an improvement in viscosity in hybrid fluids at higher temperatures was observed. The experiments revealed that hybrid nanolubricant shows a significant reduction in tool flank wear and surface roughness by 38 and 11%, respectively, compared to TiO₂-based lubricant used alone. The tool wear decreased considerably by about 29 and 32% corresponding to 500 and 1,200 rpm, respectively in the case of hybrid fluid (1 wt% TiO₂+graphene) in comparison to the base oil, which considerably enhanced the tool life. Scanning electron microscopy analysis was conducted to study the mechanisms of tool wear at flank faces and crater faces. Chip morphological analysis was performed for the acceptable chips by analyzing the color and structure, depicting the amount of heat generation at the tool–workpiece interface. The results establish that synergism of GnP with TiO₂ enhances the tribological properties and hence provides a greener and efficient lubrication methodology.

摘要

本工作旨在研究二氧化钛（TiO _2）和石墨烯（GnP）纳米颗粒添加剂对可生物降解植物油（米糠）的流变和加工特性的协同作用。米糠油已通过最小量润滑（MQL）技术用于M2钢的车削。不同浓度的由单声道的重量（0.5和1重量％）（米糠油/二氧化钛的效果₂）和混合（米糠油/二氧化钛₂/石墨烯）纳米流体已被研究。对单油和混合油的流变学研究表明，随着纳米颗粒浓度的增加，粘度有所提高。此外，观察到混合流体在较高温度下的粘度改善。实验表明，与单独使用的TiO ₂基润滑剂相比，杂化纳米润滑剂分别显着降低了刀具侧面磨损和表面粗糙度，分别降低了38％和11％。在混合流体（1 wt％TiO ₂+石墨烯）与基础油相比，大大延长了工具寿命。进行了扫描电子显微镜分析，以研究刀具在侧面和凹坑表面的磨损机理。通过分析颜色和结构，对可接受的切屑进行切屑形态分析，描绘了工具-工件界面处的发热量。结果表明，GnP与TiO _2的协同作用增强了摩擦学性能，因此提供了一种更绿色，更有效的润滑方法。