The cooperative effect of laser surface texturing(LST) and double glow plasma surface alloying on tribological performance of lubricated sliding contacts was investigated.A Nd:YAG laser was used to generate microdimpl...The cooperative effect of laser surface texturing(LST) and double glow plasma surface alloying on tribological performance of lubricated sliding contacts was investigated.A Nd:YAG laser was used to generate microdimples on steel surfaces. Dimples with the diameter of 150μm and the depth of 30-35μm distributed circumferentially on the disc surface.The alloying element Cr was sputtered to the laser texturing steel surface by double glow plasma technique.A deep diffusion layer with a thickness of 30μm and a high hardness of HV900 was formed in this alloy.Tribological experiments of three types of samples(smooth,texturing and texturing+alloying) were conducted with a ring-on-disc tribometer to simulate the face seal.It is found that,in comparison with smooth steel surfaces,the laser texturing samples significantly reduce the friction coefficient.Moreover,the lower wear rate of the sample treated with the two surface techniques is observed.展开更多
Chrome steels are used in bearings since they possess high strength and wear resistance.However,when those parts are in service,failure happens due to sliding friction before the lifetime.To improve the durability of ...Chrome steels are used in bearings since they possess high strength and wear resistance.However,when those parts are in service,failure happens due to sliding friction before the lifetime.To improve the durability of the American Iron and Steel Institute(AISI)52100 chromium steel,in this work,the effect of laser surface texturing(LST)was analyzed.With the different patterns of circle and ellipse comparing with the untextured samples,the wear behavior was investigated using the pin-on-disc tribometer.The lubricant used for wear analysis is semisolid lithium grease National Lubricating Grease Institute lubricant(SKF NLGI-3).Sliding wear analysis was conducted at different loads of 10 N,30 N and 50 N for the sliding speed of 750 r/min and 1400 r/min.The wear morphology was analyzed using a scanning electron microscope(SEM).The roughness of the samples was found using a white light interferometer.The effect of different patterns like circle and ellipse,alter the friction and wear properties of chromium alloy was observed compared with the untextured samples.LST shows considerable reduction in friction and wear for ellipsoidal pattern compared with the circular pattern because of wear debris and lubricant getting trapped.展开更多
Superhydrophobic surfaces have attracted extensive interests and researches into their fundamentals and potential applications.Laser texturing provides the convenience to fabricate the hierarchical micro/nanostructure...Superhydrophobic surfaces have attracted extensive interests and researches into their fundamentals and potential applications.Laser texturing provides the convenience to fabricate the hierarchical micro/nanostructures for superhydrophobicity.However,after laser texturing,long wettability transition time from superhydrophilicity to superhydrophobicity is a barrier to mass production and practical industrial applications.External stimuli have been applied to change the surface composition and/or the surface morphology to reduce wettability transition time.Herein,by temperature tuning,wettability transition of laser textured brass surfaces is investigated.Scanning electron microscopy and surface contact angle measurement are employed to characterize the surface morphology and wettability behavior of the textured brass surfaces.By low-temperature heating(100℃~150℃),partial deoxidation of the top Cu O layer occurs to form hydrophobic Cu_2O.Therefore,superhydrophobicity without any chemical coating and surface modification could be achieved in a short time.Furthermore,after low-temperature heating,the low adhesive force between the water droplet and the sample surface is demonstrated for the laser textured brass surface.This study provides a simple method to fabricate the micro/nanostructure surfaces with controllable wettability for the potential applications.展开更多
基金Project(2007046) supported by High Technology Research Project of Jiangsu Province,China
文摘The cooperative effect of laser surface texturing(LST) and double glow plasma surface alloying on tribological performance of lubricated sliding contacts was investigated.A Nd:YAG laser was used to generate microdimples on steel surfaces. Dimples with the diameter of 150μm and the depth of 30-35μm distributed circumferentially on the disc surface.The alloying element Cr was sputtered to the laser texturing steel surface by double glow plasma technique.A deep diffusion layer with a thickness of 30μm and a high hardness of HV900 was formed in this alloy.Tribological experiments of three types of samples(smooth,texturing and texturing+alloying) were conducted with a ring-on-disc tribometer to simulate the face seal.It is found that,in comparison with smooth steel surfaces,the laser texturing samples significantly reduce the friction coefficient.Moreover,the lower wear rate of the sample treated with the two surface techniques is observed.
文摘Chrome steels are used in bearings since they possess high strength and wear resistance.However,when those parts are in service,failure happens due to sliding friction before the lifetime.To improve the durability of the American Iron and Steel Institute(AISI)52100 chromium steel,in this work,the effect of laser surface texturing(LST)was analyzed.With the different patterns of circle and ellipse comparing with the untextured samples,the wear behavior was investigated using the pin-on-disc tribometer.The lubricant used for wear analysis is semisolid lithium grease National Lubricating Grease Institute lubricant(SKF NLGI-3).Sliding wear analysis was conducted at different loads of 10 N,30 N and 50 N for the sliding speed of 750 r/min and 1400 r/min.The wear morphology was analyzed using a scanning electron microscope(SEM).The roughness of the samples was found using a white light interferometer.The effect of different patterns like circle and ellipse,alter the friction and wear properties of chromium alloy was observed compared with the untextured samples.LST shows considerable reduction in friction and wear for ellipsoidal pattern compared with the circular pattern because of wear debris and lubricant getting trapped.
基金supported by the National Natural Science Foundation of China (U1609209)Open Program of Laser Precision Machining Engineering Technology Research Center of Fujian Province (2016JZA001)
文摘Superhydrophobic surfaces have attracted extensive interests and researches into their fundamentals and potential applications.Laser texturing provides the convenience to fabricate the hierarchical micro/nanostructures for superhydrophobicity.However,after laser texturing,long wettability transition time from superhydrophilicity to superhydrophobicity is a barrier to mass production and practical industrial applications.External stimuli have been applied to change the surface composition and/or the surface morphology to reduce wettability transition time.Herein,by temperature tuning,wettability transition of laser textured brass surfaces is investigated.Scanning electron microscopy and surface contact angle measurement are employed to characterize the surface morphology and wettability behavior of the textured brass surfaces.By low-temperature heating(100℃~150℃),partial deoxidation of the top Cu O layer occurs to form hydrophobic Cu_2O.Therefore,superhydrophobicity without any chemical coating and surface modification could be achieved in a short time.Furthermore,after low-temperature heating,the low adhesive force between the water droplet and the sample surface is demonstrated for the laser textured brass surface.This study provides a simple method to fabricate the micro/nanostructure surfaces with controllable wettability for the potential applications.
