Nanoparticle-enhanced coolants(NPECs)are increasingly used in minimum quantity lubrication(MQL)machining as a green lubricant to replace conventional cutting fluids to meet the urgent need for carbon emissions and ach...Nanoparticle-enhanced coolants(NPECs)are increasingly used in minimum quantity lubrication(MQL)machining as a green lubricant to replace conventional cutting fluids to meet the urgent need for carbon emissions and achieve sustainable manufacturing.However,the thermophysical properties of NPEC during processing remain unclear,making it difficult to provide precise guidance and selection principles for industrial applications.Therefore,this paper reviews the action mechanism,processing properties,and future development directions of NPEC.First,the laws of influence of nano-enhanced phases and base fluids on the processing performance are revealed,and the dispersion stabilization mechanism of NPEC in the preparation process is elaborated.Then,the unique molecular structure and physical properties of NPECs are combined to elucidate their unique mechanisms of heat transfer,penetration,and antifriction effects.Furthermore,the effect of NPECs is investigated on the basis of their excellent lubricating and cooling properties by comprehensively and quantitatively evaluating the material removal characteristics during machining in turning,milling,and grinding applications.Results showed that turning of Ti‒6Al‒4V with multi-walled carbon nanotube NPECs with a volume fraction of 0.2%resulted in a 34%reduction in tool wear,an average decrease in cutting force of 28%,and a 7%decrease in surface roughness Ra,compared with the conventional flood process.Finally,research gaps and future directions for further applications of NPECs in the industry are presented.展开更多
Benefiting from a principally contaminant-free and well-defined surface,single-crystal electrodes offer new insights into interfacial processes and are important in electrochemistry.The early impetus for using single-...Benefiting from a principally contaminant-free and well-defined surface,single-crystal electrodes offer new insights into interfacial processes and are important in electrochemistry.The early impetus for using single-crystal electrodes in electrocatalysis was to investigate the surface structure at the atomic level for the reactions that are sensitive to the surface.These studies were usually performed in an ultra-high vacuum with atomic force microscopy(AFM),scanning tunneling microscope(STM),and X-ray methods to avoid the contamination.However,such characterizations are limited in their ability to identify chemical species definitively,a limitation that has similarly plagued the study of single-crystals.Recent advances in shellisolated nanoparticle-enhanced Raman spectroscopy(SHINERS)have enabled the detection of reaction intermediates on singlecrystal electrodes,in which shell-isolated nanoparticles on the single-crystal electrode can enhance the Raman signal from the surface,without changing the surface structure and electrochemical response.Thus,this work aims to review recent advances in Raman spectroelectrochemical studies on single-crystal electrode surfaces.The discussion focuses on how SHINERS technology has enabled the effective detection of intermediate species and,when combined with the electrochemical method,has yielded novel insights into the dynamic evolution of surface structure and electrocatalytic reaction mechanisms.Finally,the challenges and future of single-crystal electrodes are introduced.展开更多
基金the National Key R&D Program of China(Grant No.2020YFB2010500)the National Natural Science Foundation of China(Grant Nos.52105457 and 51975305)+2 种基金the Special Fund of Taishan Scholars Project,China(Grant No.tsqn202211179)the Youth Talent Promotion Project in Shandong,China(Grant No.SDAST2021qt12)the Natural Science Foundation of Shandong Province,China(Grant Nos.ZR2023QE057,ZR2022QE028,ZR2021QE116,and ZR2020KE027).
文摘Nanoparticle-enhanced coolants(NPECs)are increasingly used in minimum quantity lubrication(MQL)machining as a green lubricant to replace conventional cutting fluids to meet the urgent need for carbon emissions and achieve sustainable manufacturing.However,the thermophysical properties of NPEC during processing remain unclear,making it difficult to provide precise guidance and selection principles for industrial applications.Therefore,this paper reviews the action mechanism,processing properties,and future development directions of NPEC.First,the laws of influence of nano-enhanced phases and base fluids on the processing performance are revealed,and the dispersion stabilization mechanism of NPEC in the preparation process is elaborated.Then,the unique molecular structure and physical properties of NPECs are combined to elucidate their unique mechanisms of heat transfer,penetration,and antifriction effects.Furthermore,the effect of NPECs is investigated on the basis of their excellent lubricating and cooling properties by comprehensively and quantitatively evaluating the material removal characteristics during machining in turning,milling,and grinding applications.Results showed that turning of Ti‒6Al‒4V with multi-walled carbon nanotube NPECs with a volume fraction of 0.2%resulted in a 34%reduction in tool wear,an average decrease in cutting force of 28%,and a 7%decrease in surface roughness Ra,compared with the conventional flood process.Finally,research gaps and future directions for further applications of NPECs in the industry are presented.
基金supported by the National Key Research and Development Program of China (2020YFB1505800)the National Natural Science Foundation of China (21925404,22005130,and 21991151)the China Postdoctoral Science Foundation (BX20220187)。
文摘Benefiting from a principally contaminant-free and well-defined surface,single-crystal electrodes offer new insights into interfacial processes and are important in electrochemistry.The early impetus for using single-crystal electrodes in electrocatalysis was to investigate the surface structure at the atomic level for the reactions that are sensitive to the surface.These studies were usually performed in an ultra-high vacuum with atomic force microscopy(AFM),scanning tunneling microscope(STM),and X-ray methods to avoid the contamination.However,such characterizations are limited in their ability to identify chemical species definitively,a limitation that has similarly plagued the study of single-crystals.Recent advances in shellisolated nanoparticle-enhanced Raman spectroscopy(SHINERS)have enabled the detection of reaction intermediates on singlecrystal electrodes,in which shell-isolated nanoparticles on the single-crystal electrode can enhance the Raman signal from the surface,without changing the surface structure and electrochemical response.Thus,this work aims to review recent advances in Raman spectroelectrochemical studies on single-crystal electrode surfaces.The discussion focuses on how SHINERS technology has enabled the effective detection of intermediate species and,when combined with the electrochemical method,has yielded novel insights into the dynamic evolution of surface structure and electrocatalytic reaction mechanisms.Finally,the challenges and future of single-crystal electrodes are introduced.
