This study addresses the lubrication challenges posed by oil-water mixtures that arise when vessels encounter adverse maritime conditions,including collisions,grounding,and reefing,which can lead to failures in lubric...This study addresses the lubrication challenges posed by oil-water mixtures that arise when vessels encounter adverse maritime conditions,including collisions,grounding,and reefing,which can lead to failures in lubrication systems during navigation.The research focuses on three representative ship tail-bearing composites:polymer material(K4),thordon material(SR),and tenmat material(FR).Various volume fractions of oil-water mixtures were prepared,and the rheological properties of these mixtures were examined using a rotational rheometer(MCR102).Additionally,the variation of friction coefficients of the composites about load and linear velocity under different oil-water mixtures was analyzed using a Ring-Block Friction and Wear Testing Machine.Following the experiments,the surface morphology of the composites was assessed,and the wear mechanisms were analyzed using a laser interferometric surface profiler(LI-type),a confocal laser microscope(CLSM),and a scanning electron microscope(SEM).The findings indicate that,under all lubrication conditions,the friction coefficients of the three materials exhibit a gradual decrease with increasing load and linear velocity.Furthermore,the wear of the materials initially increases and then decreases with rising oil content,with higher oil concentrations in the oil-water mixture correlating with reduced wear.The study reveals that the three materials experience significant abrasive and adhesive wear under adverse oil-water mixing conditions.This research offers valuable insights for developing friction substitutes for oil-water mixing bearings in specialized operational environments and guides the design of friction components in such bearings.展开更多
To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication phase.Subsequently,t...To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication phase.Subsequently,the CoCrAlYTa-xCNTs(x=0,1,2,and 4;wt%)composite coatings were prepared by laserinduction hybrid cladding(LIHC),and the microstructure and wear resistance of coatings were systematically analyzed.Results show that the coatings are mainly composed of TaC,y-(Co,Cr)andβ-(Co,Cr)Al.As the CNTs content increases from 0 wt%to 4 wt%,the volume fraction of TaC increases from 13.11 vol%to 16.12 vol%.Meanwhile,the nano-hardness ofγ-(Co,Cr)andβ-(Co,Cr)Al are improved from 7.49 and 9.72 to 9.36 and 11.19 GPa,respectively.As a result,the microhardness of coating increases from HV536.25 to HV 738.16,the wear rate decreases from32.4×10^(-3)to 6.1×10^(-3)mg·m^(-1),and the average friction coefficient decreases from 0.55 to 0.44.The good wear performance of the coating is attributed to the formation of TaC and the existence of remained CNTs lubricant film.展开更多
基金supported by the National Natural Science Foundation of China(U2341284,51579198)the Postdoctoral Fellowship Program of CPSF under Grant Number GZB20240584the Fundamental Research Funds for the Central Universities(WUT:3120624441).
文摘This study addresses the lubrication challenges posed by oil-water mixtures that arise when vessels encounter adverse maritime conditions,including collisions,grounding,and reefing,which can lead to failures in lubrication systems during navigation.The research focuses on three representative ship tail-bearing composites:polymer material(K4),thordon material(SR),and tenmat material(FR).Various volume fractions of oil-water mixtures were prepared,and the rheological properties of these mixtures were examined using a rotational rheometer(MCR102).Additionally,the variation of friction coefficients of the composites about load and linear velocity under different oil-water mixtures was analyzed using a Ring-Block Friction and Wear Testing Machine.Following the experiments,the surface morphology of the composites was assessed,and the wear mechanisms were analyzed using a laser interferometric surface profiler(LI-type),a confocal laser microscope(CLSM),and a scanning electron microscope(SEM).The findings indicate that,under all lubrication conditions,the friction coefficients of the three materials exhibit a gradual decrease with increasing load and linear velocity.Furthermore,the wear of the materials initially increases and then decreases with rising oil content,with higher oil concentrations in the oil-water mixture correlating with reduced wear.The study reveals that the three materials experience significant abrasive and adhesive wear under adverse oil-water mixing conditions.This research offers valuable insights for developing friction substitutes for oil-water mixing bearings in specialized operational environments and guides the design of friction components in such bearings.
基金financially supported by the National Natural Science Foundation of China(Nos.52005217 and 51261026)the Basic and Applied Basic Research Fund Project of Guangdong Province in China(Nos.2023A1515012684,2021A1515010523 and 2020A1515110020)+4 种基金the University Research Platform and Research Projects of Guangdong Education Department(No.2022ZDZX3003)the Open Foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials(No.2022GXYSOF18)Guanxi Key Laboratory of Information Materials(No.221012-K)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2021WNLOKF010)the Fundamental Research Funds for the Central Universities(No.21622110)。
文摘To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication phase.Subsequently,the CoCrAlYTa-xCNTs(x=0,1,2,and 4;wt%)composite coatings were prepared by laserinduction hybrid cladding(LIHC),and the microstructure and wear resistance of coatings were systematically analyzed.Results show that the coatings are mainly composed of TaC,y-(Co,Cr)andβ-(Co,Cr)Al.As the CNTs content increases from 0 wt%to 4 wt%,the volume fraction of TaC increases from 13.11 vol%to 16.12 vol%.Meanwhile,the nano-hardness ofγ-(Co,Cr)andβ-(Co,Cr)Al are improved from 7.49 and 9.72 to 9.36 and 11.19 GPa,respectively.As a result,the microhardness of coating increases from HV536.25 to HV 738.16,the wear rate decreases from32.4×10^(-3)to 6.1×10^(-3)mg·m^(-1),and the average friction coefficient decreases from 0.55 to 0.44.The good wear performance of the coating is attributed to the formation of TaC and the existence of remained CNTs lubricant film.
