化学镀镍磷合金镀层的耐蚀性已很难满足现代工业日益提高的防腐蚀要求,为提高其综合性能,拓宽应用范围,在化学镀镍磷合金液中加入硫酸铜和氯化铬制备镍铜铬磷四元合金镀层,优选出最佳工艺条件为:15g/L硫酸镍,40g/L次磷酸钠,0.2g/L硫酸铜...化学镀镍磷合金镀层的耐蚀性已很难满足现代工业日益提高的防腐蚀要求,为提高其综合性能,拓宽应用范围,在化学镀镍磷合金液中加入硫酸铜和氯化铬制备镍铜铬磷四元合金镀层,优选出最佳工艺条件为:15g/L硫酸镍,40g/L次磷酸钠,0.2g/L硫酸铜,0.5g/L钼酸钠,0.5mg/L稳定剂(由含氮有机化合物或含碘化合物配制而成),40g/L配位剂(以一种多羟基羧酸作主配位剂,一种多元羧酸作辅助配位剂),20g/L乙酸钠,10g/L三氯化铬,表面活性剂(聚乙二醇和含氟表面活性剂)适量,pH值4.0～5.0,温度80～90℃,时间20min。研究了镀液中主要成分和工艺条件对合金镀层外观、沉积速度、耐蚀性的影响。检测了化学镀Ni Cu Cr P合金镀层的性能,镀层中含8%～9%Cr,2%～3%Cu,78%～85%Ni。结果表明,所得的镍铜铬磷四元合金镀层结晶细致,达镜面光亮,其耐蚀性、孔隙率和硬度等性能均优于化学镀镍磷合金层。展开更多
On purpose of studying the sluggish diffusion of high-entropy alloys, three different face centered cubic Co-Cr-Cu-Fe-Ni high-entropy alloys were prepared, and assembled into three groups of sandwich- type diffusion m...On purpose of studying the sluggish diffusion of high-entropy alloys, three different face centered cubic Co-Cr-Cu-Fe-Ni high-entropy alloys were prepared, and assembled into three groups of sandwich- type diffusion multiple annealed at 1273, 1323, and 1373 K respectively. By means of the electron probe microanalyzer technique and recently developed numerical inverse method, the composition- dependent interdiffusivities at different temperatures were effectively evaluated by minimizing the residual between the model-predicted compositions/interdiffusion fluxes and the respectively experi- mental ones. After that, the tracer diffusivities were predicted based on the assessed mobility parameters and thermodynamic descriptions with the simplified ideal solution model. The comprehensive compari- son between the interdiffusivities/tracer diffusivities in the Co-Cr-Cu-Fe-Ni high-entropy alloys and those in sub-binary, ternary, quaternary and other quinary alloys indicates that the sluggish diffusion exists in interdiffusion instead of tracer diffusion for the present Co-Cr-Cu-Fe-Ni high-entropy alloys.展开更多
Cr-Cu-N coatings with copper content from 0 at%to 6.8 at%were deposited on silicon and M2 steel by ion beam assisted magnetron sputtering.The microstructure and composition of the coatings were characterized using SEM...Cr-Cu-N coatings with copper content from 0 at%to 6.8 at%were deposited on silicon and M2 steel by ion beam assisted magnetron sputtering.The microstructure and composition of the coatings were characterized using SEM,GDOES,XRD and XPS.The mechanical properties of the coatings were tested on a standard hardness tester.The tribological behavior of the coatings in dry wear condition was studied by means of ball-on-disc wear test.The experimental results show that addition of copper can restrict the columnar crystal growing to a certain degree.XRD and XPS analysis indicate that coatings are mainly composed of Cr and CrN phase.Cu is mainly existed in a free state in the coatings.Copper adding has no obvious effects on the hardness of the coatings.However,the coatings fracture toughness can be improved by doped copper.The coefficient of friction of the coatings against bearing steel is in the range of 0.25-0.6 changing with the copper content.The coating with 2.6 at%copper shows the lowest coefficient of friction about 0.25 and wear rate which is about one tenth of that of the coating with 6.8 at%copper.The higher coefficient of friction and wear rate of the coating with 6.8at%copper may be attributed to its lower bonding strength.展开更多
文摘化学镀镍磷合金镀层的耐蚀性已很难满足现代工业日益提高的防腐蚀要求,为提高其综合性能,拓宽应用范围,在化学镀镍磷合金液中加入硫酸铜和氯化铬制备镍铜铬磷四元合金镀层,优选出最佳工艺条件为:15g/L硫酸镍,40g/L次磷酸钠,0.2g/L硫酸铜,0.5g/L钼酸钠,0.5mg/L稳定剂(由含氮有机化合物或含碘化合物配制而成),40g/L配位剂(以一种多羟基羧酸作主配位剂,一种多元羧酸作辅助配位剂),20g/L乙酸钠,10g/L三氯化铬,表面活性剂(聚乙二醇和含氟表面活性剂)适量,pH值4.0～5.0,温度80～90℃,时间20min。研究了镀液中主要成分和工艺条件对合金镀层外观、沉积速度、耐蚀性的影响。检测了化学镀Ni Cu Cr P合金镀层的性能,镀层中含8%～9%Cr,2%～3%Cu,78%～85%Ni。结果表明,所得的镍铜铬磷四元合金镀层结晶细致,达镜面光亮,其耐蚀性、孔隙率和硬度等性能均优于化学镀镍磷合金层。
基金financially supported by the National Natural Science Foundation of China(Grant No.51474239)the National Key Research and Development Program of China(Grant No.2016YFB0301101)+1 种基金financial support from the Huxiang Youth Talent Plan released by Hunan Province,Chinathe project supported by State Key Laboratory of Powder Metallurgy Foundation,Central South University,Changsha,China
文摘On purpose of studying the sluggish diffusion of high-entropy alloys, three different face centered cubic Co-Cr-Cu-Fe-Ni high-entropy alloys were prepared, and assembled into three groups of sandwich- type diffusion multiple annealed at 1273, 1323, and 1373 K respectively. By means of the electron probe microanalyzer technique and recently developed numerical inverse method, the composition- dependent interdiffusivities at different temperatures were effectively evaluated by minimizing the residual between the model-predicted compositions/interdiffusion fluxes and the respectively experi- mental ones. After that, the tracer diffusivities were predicted based on the assessed mobility parameters and thermodynamic descriptions with the simplified ideal solution model. The comprehensive compari- son between the interdiffusivities/tracer diffusivities in the Co-Cr-Cu-Fe-Ni high-entropy alloys and those in sub-binary, ternary, quaternary and other quinary alloys indicates that the sluggish diffusion exists in interdiffusion instead of tracer diffusion for the present Co-Cr-Cu-Fe-Ni high-entropy alloys.
基金The National Natural Science Foundation of China(50771070)Shanxi Province Science and Technology Key Project(20100321078-02)
文摘Cr-Cu-N coatings with copper content from 0 at%to 6.8 at%were deposited on silicon and M2 steel by ion beam assisted magnetron sputtering.The microstructure and composition of the coatings were characterized using SEM,GDOES,XRD and XPS.The mechanical properties of the coatings were tested on a standard hardness tester.The tribological behavior of the coatings in dry wear condition was studied by means of ball-on-disc wear test.The experimental results show that addition of copper can restrict the columnar crystal growing to a certain degree.XRD and XPS analysis indicate that coatings are mainly composed of Cr and CrN phase.Cu is mainly existed in a free state in the coatings.Copper adding has no obvious effects on the hardness of the coatings.However,the coatings fracture toughness can be improved by doped copper.The coefficient of friction of the coatings against bearing steel is in the range of 0.25-0.6 changing with the copper content.The coating with 2.6 at%copper shows the lowest coefficient of friction about 0.25 and wear rate which is about one tenth of that of the coating with 6.8 at%copper.The higher coefficient of friction and wear rate of the coating with 6.8at%copper may be attributed to its lower bonding strength.
