Because of an unfortunate mistake by authors,the Project(5227010679)of Foundation item was wrong.The corrected Project is shown as follows:Project(52271073).
The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on acti...The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on active anodic oxide film and the structure and properties of the composite coating were studied by several surface and electrochemical techniques.The results showed that Ag nanograins with an average size of 10 nm were embedded into the anodic oxide film with pores of 0.1−2μm.Ag nanoparticles provided a catalytic site for the deposition of Ni-B alloy,and the Ni crystal nucleus was first grown in horizontal mode and then in cylindrical mode.The corrosion potential of the composite coating increased by 1.37 V and the corrosion current reduced two orders of magnitude due to the subsequent deposition of Ni-P alloy.The high corrosion resistance was attributed to the misaligning of these micro defects in the three different layers and the amorphous structure of the Ni-P alloy in the outer layer.These findings provide a new idea for electroless nickel plating on anodic oxide film.展开更多
In recent years,magnesium(Mg)has evolved as a salient material,in affiliation with electroless nickel(Ni)coating,which have found applications in automobiles,aerospace and confederate fields attributing to its excelle...In recent years,magnesium(Mg)has evolved as a salient material,in affiliation with electroless nickel(Ni)coating,which have found applications in automobiles,aerospace and confederate fields attributing to its excellent inherent weight sensitive properties.However,being acknowledged for its remarkable auxiliary properties like flexible machining,appreciable weight sensitivity and ability to be patently diecast into mesh constructs,magnesium is prejudiced by aeronautical standards predominantly for its inferior corrosion resistance properties.In this sense,electroless nickel plating on magnesium and its alloys has been suggested to extricate it from corrosion problem and make it more competitive in industrial and defence applications.Autocatalytic fixation of metal ions onto respective substrates accrues and alters their mechanical,electrochemical and tribological properties,destitute of any electric current aid.This proficiently identified technique is prosecuted with the assistance of a series of sequenced operations involving a prior pretreatment,which corresponds to the chemical cleaning of the substrate surface;electroless coating;and a later activation process which is a mild etching of the electroless coated surface.The susceptibility of magnesium to this methodology has advanced and propagated its exercise and applicability in aircraft,satellites and allied aeronautical fields.Contemporarily,researchers have proposed various eco-friendly and modified duplex and composite coatings which have transmuted properties of these appendages by tailoring alloy compositions and reagents employed.This review article systematically colligates various considerations and evaluations on electroless nickel applications of magnesium and its alloys and explicates how it anchors its practice in the respective domains.Furthermore,a comprehensive analysis is devised based on the pre-existing treatment methods for accomplishing the same.展开更多
Quartz optical fibers are of great significance in many fields. For example,they can be used to fabricate strain sensors and temperature sensors.If the surface of optical fibers is metal-coated by the electroless plat...Quartz optical fibers are of great significance in many fields. For example,they can be used to fabricate strain sensors and temperature sensors.If the surface of optical fibers is metal-coated by the electroless plating method, the measuring precision and stability of the optical fiber sensors can be improved remarkably, additionally the life-span of sensors can be prolonged.In this work, an electroless nickel-phosphor plating process for optical fibers was presented.The influences of the content of NaH 2PO 2·H 2O, bath pH value and temperature and the plating deposition rate on the quality of the plating coatings were studied with orthogonal testing.The results indicated that the content of NaH 2PO 2·H 2O was the key factor, which influenced the adhesion force of the plating coatings.The nickel-phosphor plating bath presented in this work possessed excellent stability and the plating deposition rate could be accelerated.Using the process described in this work, nickel-phosphor coatings with great brightness and high adhesion force can be prepared successfully.Optimum conditions were: NiSO 4 30 g·L -1, NaH 2PO 2·H 2O 20 g·L -1, C 3H 6O 3 4 ml·L -1, Na 2CO 3 3 g·L -1, NH 4Cl 4 g·L -1, saccharin 1 mg·L -1, temperature 84 ℃, pH 4.6.展开更多
文摘Because of an unfortunate mistake by authors,the Project(5227010679)of Foundation item was wrong.The corrected Project is shown as follows:Project(52271073).
基金Project(5227010679)supported by the National Natural Science Foundation of China。
文摘The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on active anodic oxide film and the structure and properties of the composite coating were studied by several surface and electrochemical techniques.The results showed that Ag nanograins with an average size of 10 nm were embedded into the anodic oxide film with pores of 0.1−2μm.Ag nanoparticles provided a catalytic site for the deposition of Ni-B alloy,and the Ni crystal nucleus was first grown in horizontal mode and then in cylindrical mode.The corrosion potential of the composite coating increased by 1.37 V and the corrosion current reduced two orders of magnitude due to the subsequent deposition of Ni-P alloy.The high corrosion resistance was attributed to the misaligning of these micro defects in the three different layers and the amorphous structure of the Ni-P alloy in the outer layer.These findings provide a new idea for electroless nickel plating on anodic oxide film.
文摘In recent years,magnesium(Mg)has evolved as a salient material,in affiliation with electroless nickel(Ni)coating,which have found applications in automobiles,aerospace and confederate fields attributing to its excellent inherent weight sensitive properties.However,being acknowledged for its remarkable auxiliary properties like flexible machining,appreciable weight sensitivity and ability to be patently diecast into mesh constructs,magnesium is prejudiced by aeronautical standards predominantly for its inferior corrosion resistance properties.In this sense,electroless nickel plating on magnesium and its alloys has been suggested to extricate it from corrosion problem and make it more competitive in industrial and defence applications.Autocatalytic fixation of metal ions onto respective substrates accrues and alters their mechanical,electrochemical and tribological properties,destitute of any electric current aid.This proficiently identified technique is prosecuted with the assistance of a series of sequenced operations involving a prior pretreatment,which corresponds to the chemical cleaning of the substrate surface;electroless coating;and a later activation process which is a mild etching of the electroless coated surface.The susceptibility of magnesium to this methodology has advanced and propagated its exercise and applicability in aircraft,satellites and allied aeronautical fields.Contemporarily,researchers have proposed various eco-friendly and modified duplex and composite coatings which have transmuted properties of these appendages by tailoring alloy compositions and reagents employed.This review article systematically colligates various considerations and evaluations on electroless nickel applications of magnesium and its alloys and explicates how it anchors its practice in the respective domains.Furthermore,a comprehensive analysis is devised based on the pre-existing treatment methods for accomplishing the same.
文摘Quartz optical fibers are of great significance in many fields. For example,they can be used to fabricate strain sensors and temperature sensors.If the surface of optical fibers is metal-coated by the electroless plating method, the measuring precision and stability of the optical fiber sensors can be improved remarkably, additionally the life-span of sensors can be prolonged.In this work, an electroless nickel-phosphor plating process for optical fibers was presented.The influences of the content of NaH 2PO 2·H 2O, bath pH value and temperature and the plating deposition rate on the quality of the plating coatings were studied with orthogonal testing.The results indicated that the content of NaH 2PO 2·H 2O was the key factor, which influenced the adhesion force of the plating coatings.The nickel-phosphor plating bath presented in this work possessed excellent stability and the plating deposition rate could be accelerated.Using the process described in this work, nickel-phosphor coatings with great brightness and high adhesion force can be prepared successfully.Optimum conditions were: NiSO 4 30 g·L -1, NaH 2PO 2·H 2O 20 g·L -1, C 3H 6O 3 4 ml·L -1, Na 2CO 3 3 g·L -1, NH 4Cl 4 g·L -1, saccharin 1 mg·L -1, temperature 84 ℃, pH 4.6.
