纳米生物润滑剂微量润滑磨削性能研究进展

Research Progress on the Grinding Performance of Nanobiolubricant Minimum Quantity Lubrication

微量润滑是针对浇注式和干磨削技术缺陷的理想替代方案,为了满足高温高压边界条件下磨削区抗磨减摩与强化换热需求,进行了纳米生物润滑剂作为微量润滑的雾化介质探索性研究。然而,由于纳米生物润滑剂的理化特性与磨削性能之间映射关系尚不清晰,纳米生物润滑剂作为冷却润滑介质在磨削中的应用仍然面临着严峻的挑战。为解决上述需求,本文基于摩擦学、传热学和工件表面完整性对纳米生物润滑剂的磨削性能进行综合性评估。首先,从基液和纳米添加相的角度阐述了纳米生物润滑剂的理化特性。其次,结合纳米生物润滑剂独特的成膜和传热能力,分析了纳米生物润滑剂优异的磨削性能。结果表明,纳米生物润滑剂优异的传热和极压成膜性能显著改善了磨削区的极端摩擦条件,相比于传统微量润滑,表面粗糙度值(Ra)可降低约10%~22.4%。进一步地,阐明了多场赋能调控策略下,磨削区纳米生物润滑剂浸润与热传递增效机制。最后,针对纳米生物润滑剂的工程和科学瓶颈提出了展望,为纳米生物润滑剂的工业应用和科学研究提供理论指导和技术支持。

The negative impact of traditional mineral oil based grinding fluids on environmental protection,human health and manufacturing costs can hardly meet the development needs of green manufacturing.Minimum quantity lubrication(MQL)atomizes a small amount of biodegradable biolubricants with compressed air to form micro droplets to providing lubrication and anti-wear effects,which is an ideal alternative to flooding and dry grinding technology defects.In order to meet the requirements of anti-wear and friction reduction and enhanced heat transfer in the grinding zone under high temperature and high pressure boundary conditions,nanobiolubricants have been widely investigated as atomised media for minimum quantity lubrication.However,the application of nanobiolubricants as cooling and lubrication media in grinding still faces serious challenges due to the unclear mapping relationship between the physicochemical properties of nanobiolubricants and grinding performance.This is due to the fact that the mechanisms of action of nanoparticles on lubricants is a result of multiple coupling factors.Nanoparticles will not only improve the heat transfer and tribological properties of biological lubricants,but also increase their viscosity.However,the coupling mechanisms between the two factors are often be overlooked.In addition,as a cooling and lubrication medium,the compatibility between nanobiolubricants with different physical and chemical properties and workpiece materials also needs to be further summarized and evaluated.To address these needs,this paper presents a comprehensive assessment of the grinding performance of nanobiolubricants based on tribology,heat transfer and workpiece surface integrity.Firstly,the physicochemical properties of nanobiolubricants were described from the perspectives of base fluids and nano additive phase.And factors which influenced thermophysical properties of nanobiolubricants were analysed.Secondly,the excellent grinding performance of the nanobiolubricants was analysed in relation to their unique film-forming and heat transfer capabilities.Coolingand lubrication mechanism of nanobiolubricants in grinding process was revealed.The results showed that nanobiolubricants can be used as a high-performance cooling lubricant under the trend of reducing the supply of grinding fluids.The excellent heat transfer and extreme pressure film-forming properties of nanobiolubricants significantly improved the extreme friction conditions in the grinding zone,and the surface roughness values(Ra)could be reduced by about 10%-22.4%,grinding temperatures could be reduced by about 13%-36%compared with the traditional minimum quantity lubrication.Furtherly,the multi-field endowment modulation strategy was investigated to elucidate the mechanism of nanobiolubricant infiltration and heat transfer enhancement in the multi-field endowed grinding zone.Multiple fields such as magnetic and ultrasonic fields have improved the wetting performance of nanobiolubricant droplets,effectively avoiding the thermal damage and enabling the replacement of flood lubrication.In the grinding of hard and brittle materials,ultrasonic energy not only enhances the penetration of the grinding fluid through the pumping effect,but also reduces the brittle fracture of the material,and the surface roughness value(Ra)can be reduced by about 10%-15.7%compared with the traditional minimum quantity lubrication.Finally,an outlook for engineering and scientific bottleneck of nanobiolubricants was presented to provide theoretical guidance and technical support for the industrial application and scientific research of nanobiolubricants.