Time filter

Source Type

Jiang Y.,National Key Laboratory for Remanufacturing | Jiang Y.,Naval Flying Academy of China | Xu B.S.,National Key Laboratory for Remanufacturing | Wang H.D.,National Key Laboratory for Remanufacturing | Lu Y.H.,National Key Laboratory for Remanufacturing
Computational Materials Science | Year: 2010

The distribution of residual stresses in the sprayed coating is discussed by finite element method (FEM). With the increasing of coating thickness, residual stresses in the coating tend to change from compressive to tensile, the stress distribution along the radius of the specimen is smoother, but the concentration near the edge of coating, especially near the edge of hole, is sharper, which lead to failure of the coating. The hole radius of specimens took great effect on the distribution of residual stress near the inner radius, however, little effect on the distribution near the outer radius. © 2010 Elsevier B.V. All rights reserved.


Cheng J.B.,Hohai University | Cheng J.B.,National Key Laboratory for Remanufacturing | Liang X.B.,National Key Laboratory for Remanufacturing | Xu B.S.,National Key Laboratory for Remanufacturing
Journal of Thermal Spray Technology | Year: 2014

FeBSiNb coatings with a primarily glassy structure were prepared by arc spray processing. The as-sprayed coating was devitrified at various annealing temperatures to form different portions of crystalline phase. The effect of crystallization on the corrosion resistance of the coatings was systematically studied by potentiodynamic polarization and electrochemical impedance spectroscopy analysis in 3.5 wt.% NaCl solution. The results indicate that the as-sprayed coatings exhibit a superior corrosion resistance to the crystallized coatings with high polarization resistance, and the corrosion resistance of the coating deteriorates with the increase in the amount of crystalline phase. The corrosion resistance of both as-sprayed and devitrified coatings is explained in terms of chemical and structural characteristics of the alloys. © 2013 ASM International.


Cheng J.B.,Hohai University | Cheng J.B.,National Key Laboratory for Remanufacturing | Liang X.B.,National Key Laboratory for Remanufacturing | Wang Z.H.,Hohai University | Xu B.S.,National Key Laboratory for Remanufacturing
Journal of Thermal Spray Technology | Year: 2013

In this study, FeBSiNb coatings were prepared by twin wire arc spraying process. The microstructure and mechanical properties of as-sprayed coatings were characterized. The results show that the coating is adhering well and very compact with porosity of 1.2% (the value range is 0.9-1.7%). The microstructure of the coating consists of full glassy structure. The crystallization temperature, microhardness, elastic modulus, and average adhesive strength of the coating are 819 K, 16.42 GPa (the value range is 14.38-18.46 GPa), 219 GPa (the value range is 201-237 GPa), and 57.4 MPa (the value range is 55-64 MPa), respectively. The relatively wear resistance of the coating is about three times than that of 3Cr13 martensite stainless steel coating. The reasons for excellent wear resistance of FeBSiNb metallic glass coating are attributed to a uniform amorphous structure, the high ratio of hardness to elastic modulus (H/E) and the ratio of the elastic deformation energy to the total deformation energy (η value). The main failure mechanism of the coating is brittle failure and fracture. © 2013 ASM International.


Cheng J.B.,Hohai University | Cheng J.B.,National Key Laboratory for Remanufacturing | Wang Z.H.,Hohai University | Xu B.S.,National Key Laboratory for Remanufacturing
Journal of Thermal Spray Technology | Year: 2012

FeCrBSiNbW coatings were synthesized using robotically manipulating twin wires arc spraying system. The microstructure and mechanical properties of the coating were characterized. The coating has a laminated structure, and its porosity is 2.8%. The microstructure of the coating consists of amorphous and α-(Fe,Cr) nanocrystalline. The nanocrystalline grains with a scale of 20-75 nm are homogenously dispersed in amorphous matrix. The results show that FeCrBSiNbW coating has excellent wear and corrosion resistance. The wear resistance of the coating is about 4.6 times higher than that of 3Cr13 coating under the same testing condition. In 3.5% NaCl aqueous solution, the amorphous/nanocrystalline coating presents lower I corr values in polarization curves and higher fitted R t values in EIS plots than that of the 0Cr18Ni9 coating (chemical composition by EDAX analysis: C1.07-O12.38-Si0.49-Cr15.18-Mn0.89-Ni7.09-Fe62.24 at.%). © 2012 ASM International.


Cheng J.B.,Hohai University | Cheng J.B.,National Key Laboratory for Remanufacturing | Liang X.B.,National Key Laboratory for Remanufacturing | Xu B.S.,National Key Laboratory for Remanufacturing
Surface and Coatings Technology | Year: 2014

The microstructure and mechanical properties of the CoCrCuFeNiNb high-entropy alloy coating prepared by plasma transferred arc cladding process were investigated. Two phases are found in the prepared coating with Nb: one is face-centered-cubic solid solution phase; the other is the Laves phase of (CoCr) Nb type. The nano-indentation testing indicates that the microhardness (H), elastic modulus (E), the hardness/modulus of elasticity ratio (H/E ratio) and high resistance to plastic deformation (H3/E2) of the coating with Nb are 6.13GPa, 221GPa, 0.028 and 4.7×10-3 respectively. The CoCrCuFeNiNb coating displays excellent wear and corrosion resistance. The wear resistance of the coating with Nb is about 1.5 times higher than that of the coating without Nb under the same wet sand rubber wheel abrasion testing conditions. Compared with the coating without Nb and as-cast 304 stainless steel, the coating with Nb shows the lowest icorr values in polarization curves and the highest fitted Rf values in EIS plots in 6N hydrochloric acid solution. © 2013 Elsevier B.V.


Cheng J.B.,Hohai University | Cheng J.B.,National Key Laboratory for Remanufacturing | Liang X.B.,National Key Laboratory for Remanufacturing | Xu B.S.,National Key Laboratory for Remanufacturing
Surface and Coatings Technology | Year: 2013

FeBSiNb amorphous coatings were synthesized by arc spray processing. The effects of annealing treatments on the microstructure, elastic and mechanical properties of the coatings were investigated. Annealing below 650°C induces the formation of α-Fe phase nanocrystals. Annealing at 650°C promotes the formation of Fe3B, Fe23B6 phases and α-Fe solid solution. The as-sprayed coating displays ultra-high hardness (H>16GPa), high reduced Young's modulus (Er>210GPa) and good wear resistance. These properties are further improved after annealing treatments (H>20GPa and Er>260GPa are achieved in the fully crystallized coating). The mechanical hardening is accompanied with an increase of the ratio of hardness to elastic modulus (H/Er), the yield pressure (H3/Er2) and the elastic recovery (η value). The different microstructural mechanisms responsible for these annealing-induced changes in mechanical and elastic properties are discussed. © 2013 Elsevier B.V.


Zhu Z.,Aviation Equipment Measuring Center | Liu Y.,National Key Laboratory for Remanufacturing | Xu B.,National Key Laboratory for Remanufacturing
Advanced Materials Research | Year: 2011

Cored wires and high velocity arc spraying technique (HVAS) were used to produce high Mg content Zn-Al-Mg alloy coatings on low carbon steel substrates. The microstructures, mechanical properties and electrochemical corrosion behaviors of the Zn-Al-Mg coatings were investigated comparing with Zn and Zn-Al alloy coatings. And the electrochemical corrosion mechanisms of the coatings were discussed. The coatings show a typical aspect of layered thermal sprayed material structure. Chemical analysis of the coating indicated the composition to be Zn-14.9Al-5.9Mg-3.0O (wt.%). The main phases in the coatings are Zn, Mg2Zn11, Al12Mg17 and MgAl 2O4, together with a little Al2O3 and ZnO. The corrosion potential of Zn-Al and Zn-Al-Mg coatings decreased a little and then increased towards the noble potential. With addition of Mg, the corrosion products accumulated to form stable passive film can block off the pores in the Zn-Al-Mg coating, and thus may prevent attack on the underlying steel substrate. The Zn-Al-Mg coatings show higher electrochemical corrosion resistance in salt solution than Zn-Al coatings. © (2011) Trans Tech Publications Switzerland.


Jing X.D.,Shanghai Institute of Technology | Xu B.S.,National Key Laboratory for Remanufacturing
Applied Mechanics and Materials | Year: 2014

Main considerations for development of a virtual instrument(VI) have been presented, which include determination of algorithms, signal match, software filtering, meaesures to correct systematic errors, sampling rate, dand design of the control & diagram panels, debugging & simulating, and selection of developping platform. An example is given to illustrate the successful application of these considerations to process monitoring of brush plating. © (2014) Trans Tech Publications, Switzerland.


Xu B.-S.,National Key Laboratory for Remanufacturing
Surface Engineering | Year: 2010

Professor Tom Bell dedicated himself to the establishment of the discipline of surface engineering and contributed greatly to the development of surface engineering in China. This paper briefly overviews the four important stages in the development of surface engineering in China, i.e. single surface engineering, duplex surface engineering, nanosurface engineering and automation. © 2010 Maney Publishing.


Zhu Z.,Aviation Equipment Measuring Center | Zhang J.,Aviation Equipment Measuring Center | Xu B.,National Key Laboratory for Remanufacturing
Advanced Materials Research | Year: 2011

In order to study the effect of RE on anti-corrosion mechanism, high Mg content Zn-Al-Mg and Zn-Al-Mg-RE (where RE is Rare Earth) alloy coatings were produced on low carbon steel substrates by using cored wires and arc spraying. The electrochemical impedance spectroscopy (EIS) was used to determine the anti-corrosion mechanism of the two coatings in 5% NaCl solution. The composition and structure of corrosion products on the coatings surface have been investigated after corrosion tests by X-ray diffractometer (XRD). The results show that, Zn-Al-Mg-RE coating has superior corrosion resistance compared to Zn-Al-Mg coating due to the formation of more compact and uniform corrosion products. The self-sealing effect of the Zn-Al-Mg-RE coatings, especially for longer immersion times is extremely good. The role of the RE elements appears to be associated with the self-sealing process and the refinement of the coating microstructure. © (2011) Trans Tech Publications.

Loading National Key Laboratory for Remanufacturing collaborators
Loading National Key Laboratory for Remanufacturing collaborators