Anhui Key Laboratory of Metal Materials and Processing

Laboratory of, China

Anhui Key Laboratory of Metal Materials and Processing

Laboratory of, China
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Ran S.-L.,Anhui University of Technology | Ran S.-L.,Anhui Key Laboratory of Metal Materials and Processing | Wang D.-W.,Anhui University of Technology | Huang S.-G.,Catholic University of Leuven | And 2 more authors.
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2013

MB2-SiC (M=Ti, Zr) composites were prepared by reactive pulsed electric current sintering using MH2 as raw materials. The results indicated that the composites had a slightly textured structure with MB2 grains oriented with their (001) planes perpendicular to the direction of pressure and DC current. Fine MH2 powders improved densification and orientation of MB2 during reactive sintering process. Due to the orientation of MB2 grain, the MB2-SiC composites exhibited mechanical anisotropy. The TiB2-SiC composites showed high fracture toughness with the highest value of 7.3 MPa·m1/2 and the ZrB2-SiC composites had a high flexural strength with the value of 937 MPa, respectively.


Jin C.-G.,Anhui University of Technology | Jin C.-G.,Anhui Key Laboratory of Metal Materials and Processing | Sun C.,Anhui University of Technology | Sun C.,Anhui Key Laboratory of Metal Materials and Processing | And 4 more authors.
Gongneng Cailiao/Journal of Functional Materials | Year: 2010

The conductivity (ρ) and shielding effectiveness (SE) of eectromagnetic interference (EMI) shielding coating materials of acrylic resin matrix, alkyd paint and phenolic paint using polyaniline adoped by camphor sulfonic acid (PAn-CSA) and nickle powders as conductive fillers, KH-550 as coupling agent were measured and analyzed. The results show that the ρacrylic resin > ρalkyd paint > ρphenolic paint, SEacrylic resin > SEalkyd paint > SEphenolic paint. The surface morphologies of them were observed and analyzed. Observation results show that the dispersive uniformity of conductive fillers in matrix is acrylic resin > alkyd paint > phenolic paint, which is agreement those of conductivity and shielding effectiveness measured.


Mao A.,Anhui University of Technology | Mao A.,Anhui Key Laboratory of Metal Materials and Processing
Fenmo Yejin Jishu/Powder Metallurgy Technology | Year: 2010

Electroless plating of Ni-P coating was carried out on sintered NdFeB magnets to improve their corrosion resistance. The best technological conditions such as metallic-ion ratio Ni2+ and H2PO2-, complexing agent concentration, stabilizing agent concentration, pH value, temperature and time were optimized by testing the rate of deposition and the number of pore per area. The number of pore per area of different type of Ni-P deposits and substrate were measured and the corrosion rate were also studied in the NaCl solutions of 3.5wt%, the HCl solutions of 10vol% and the NaOH solutions of 20wt%. The result shows that all the type of deposits enhance the corrosion resistance of substrate. Also the twice electroless plating Ni-P alloy provides the best protection, with bottom film alkaline Ni-P plated and top of film acid Ni-P plated.


Hou Q.Y.,Hefei University of Technology | Hou Q.Y.,Anhui Key Laboratory of Metal Materials and Processing | Luo L.M.,Hefei University of Technology | Huang Z.Y.,Anhui Key Laboratory of Metal Materials and Processing | And 3 more authors.
Fusion Engineering and Design | Year: 2016

Tungsten coatings with 1.5 wt.% TiC (W/TiC) were fabricated by atmospheric plasma spraying (APS) and supersonic atmospheric plasma spraying (SAPS) techniques, respectively. The results showed that the typical lamellar structure of plasma spraying and columnar crystalline grains formed in the coatings. Pores located mainly at lamellar gaps in association with oxidation were also observed. TiC phase, distributed at lamellar gaps filled the gaps; and that distributed around un-melted tungsten particles and splashed debris coated the particles or debris that were linked with the TiC at lamellar gaps. The coating and linking of the retained TiC phase prevented the tungsten particles to come off from the coatings. The porosity and the oxygen content of the SAPS-W/TiC were lower than those of the APS-W/TiC coating. The mechanical response of the coatings was strongly dependent on the H/E∗ratio (H and E∗are the hardness and effective Young's modulus, respectively). The SAPS-W/TiC coating with a higher H/E∗ratio had a better ability to resist to elastic fracture and better fracture toughness as compared with the APS-W/TiC coating with a smaller H/E∗ratio. The thermal conductivity of the SAPS-W/TiC coating was greater than that of the APS-W/TiC coating. © 2016 Elsevier B.V. All rights reserved.


Hou Q.Y.,Hefei University of Technology | Hou Q.Y.,Anhui Key Laboratory of Metal Materials and Processing | Luo L.M.,Hefei University of Technology | Huang Z.Y.,Anhui Key Laboratory of Metal Materials and Processing | And 3 more authors.
Surface and Coatings Technology | Year: 2016

In this work, as a kind of rare earth hydrides, 1.5 wt.% LaH2 powder was introduced into a tungsten powder and then deposited by a supersonic atmospheric plasma spraying (SAPS) machine. The purpose was to form La2O3 in the LaH2-doped tungsten-based coating. The microstructure and properties of the undoped and LaH2-doped tungsten-based coatings were characterized using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffractometer (XRD), nano-indentation tester and Vickers hardness tester. The results showed that SAPS coatings exhibited typical lamellar microstructure. Pores located mainly at lamellar gaps in association with oxidation were also observed. The type of tungsten oxide was mainly WO3. During SAPS process, La2O3 was formed in the LaH2-doped tungsten-based coating by the transformation of LaH2. The formed La2O3 was distributed mainly at lamellar gaps, having a joining effect on the adjacent lamellae. The oxygen content, porosity and thermal conductivity of the LaH2-doped tungsten-based coating were lower than those of the undoped tungsten coating. The introduction of 1.5 wt.% LaH2 in the tungsten coating improved its ability to resist elastic fracture and improved its fracture toughness. © 2016 Elsevier B.V.


Hou Q.Y.,Hefei University of Technology | Hou Q.Y.,Anhui Key Laboratory of Metal Materials and Processing | Luo L.M.,Hefei University of Technology | Huang Z.Y.,Anhui Key Laboratory of Metal Materials and Processing | And 3 more authors.
Surface and Coatings Technology | Year: 2016

In this work, as a kind of rare earth hydrides, 1.5 wt.% LaH2 powder was introduced into a tungsten powder and then processed by atmospheric plasma spraying (APS) to form a coating. The oxidation characteristics and laser irradiation melting characteristics of the tungsten coatings with or without LaH2 addition were investigated and compared. The results showed that the coatings exhibited typical splat/lamellar microstructure. WO3, which was distributed between lamellar layers or in splats, formed in the APS-W coating by the oxidation reaction between W and O2. The introduction of LaH2 in the tungsten-based coating led to forming WO2 by a deoxidization of WO3. La2O3 with a morphology of long strip, which was distributed mainly between lamellar layers and had a filling effect on the pores, formed in the APS-W/LaH2 coating by the oxidation reaction between La/LaH2 and WO3/O2. The oxide/oxygen content and the porosity of the APS-W/LaH2 coating were apparently lower than those of the APS-W coating; and the relative density and thermal conductivity of the former were higher than those of the latter. The trends of the crack to form in the APS-W/LaH2 coating were lower than that in the APS-W coating when the two types of coatings were irradiated by a laser. The coarse elongated tungsten grains formed in laser irradiation melting sample for the APS-W coating. But the fine equiaxial tungsten grains formed in laser irradiation melting sample for the APS-W/LaH2 coating, which was mainly the result of the pinning effect of the re-precipitated spherical La2O3 particles on the re-crystalline tungsten grain boundaries. The ability of the APS-W/LaH2 coating to resist high heat loading was greater than that of the APS-W coating. © 2016 Elsevier B.V.


Hou Q.Y.,Hefei University of Technology | Hou Q.Y.,Anhui Key Laboratory of Metal Materials and Processing | Luo L.M.,Hefei University of Technology | Huang Z.Y.,Anhui Key Laboratory of Metal Materials and Processing | And 3 more authors.
Surface and Coatings Technology | Year: 2015

Three kinds of W-based composite powders containing NbC, TiC and VC were prefabricated on a carbon steel substrate, respectively. Prefabricated powders were then processed by plasma transferred arc (PTA) surfacing to form thick W-NbC, W-TiC and W-VC coatings, respectively. Microstructures and nano-indentation properties of the three kinds of coatings were investigated and compared. It was observed that, in addition to W and MC-type carbide phases, Fe7W6 phase was formed in the three kinds of coatings because of the dilution effect of Fe from the substrates. The relative contents of Fe7W6 phase in the W-NbC, W-TiC and W-VC coating were 48.1wt.%, 52.2wt.% and 36.3wt.%, respectively. Tungsten grain size in the W-NbC coating was about 2.8μm, which was smaller than that in the W-TiC coating (about 3.4μm) and that in the W-VC coating (about 4.7μm). There was no simple relation between the mechanical response and the nano-indentation hardness H or the effective Young's modulus E * alone; however, this response was strongly dependent on the ratio H/E*. For coatings with high H/E * value, the elastic recovery was also be larger. The best ability to resist elastic strain-to-failure and the highest toughness were obtained in the W-VC coating when compared with that in the W-NbC and W-TiC coatings. © 2015 Elsevier B.V.


Hou Q.Y.,Hefei University of Technology | Hou Q.Y.,Anhui Key Laboratory of Metal Materials and Processing | Ding T.T.,Anhui Key Laboratory of Metal Materials and Processing | Huang Z.Y.,Anhui Key Laboratory of Metal Materials and Processing | And 3 more authors.
Surface and Coatings Technology | Year: 2015

In this study, two types of powders were processed by plasma transferred arc (PTA) to form coatings. In the first case, Cu-Sn powder and Fe-based powder were mixed at a weight ratio of 85:15 (Cu-Sn/Fe-based). In the second case, the Cu-Sn/Fe-based powder was blended with Mo powder at a weight ratio of 96:4 (Cu-Sn/Fe-based/Mo). Therefore, the weight ratio among Cu-Sn, Fe-based, and Mo powders was 81.6:14.4:4 in the second type powders. Liquid phase separation occurred in the Cu-Sn/Fe-based and Cu-Sn/Fe-based/Mo coatings. The Fe-rich spheroids comprised γ(Fe, Ni) and M7C3 phases, as the precipitating alloy particles were distributed on the Cu-rich matrix that consisted of α(Cu, Sn) and Cu41Sn11 phases. The relative content of the Fe-rich spheroids in the Cu-Sn/Fe-based/Mo coating exceeded that in the Cu-Sn/Fe-based coating. The number of Fe-rich spheroids in the Cu-Sn/Fe-based coating increased far away from its substrate, and obvious macro-segregation could be seen close to its substrate. When Mo was further added, the numbers of Fe-rich spheroids were increased and obvious macro-segregation could not be easily found when compared to the Cu-Sn/Fe-based coating. The wear rate of the Cu-Sn/Fe-based and Cu-Sn/Fe-based/Mo coatings was lower than that of the Cu-Sn coating, and a distinct improvement on the wear rate could be obtained in the Cu-Su/Fe-based/Mo coating. The friction coefficient of the Cu-Sn/Fe-based/Mo coating exceeded that of the Cu-Sn coating but was lower than that of the Cu-Sn/Fe-based coating. The pitting corrosion resistance of the Cu-Sn/Fe-based and Cu-Sn/Fe-based/Mo coatings was higher than that of the Cu-Sn coating and the highest one could be obtained in the Cu-Sn/Fe-based/Mo coating. © 2015 Elsevier B.V.


Hou Q.Y.,Hefei University of Technology | Hou Q.Y.,Anhui Key Laboratory of Metal Materials and Processing | Ding T.T.,Anhui Key Laboratory of Metal Materials and Processing | Huang Z.Y.,Anhui Key Laboratory of Metal Materials and Processing | And 3 more authors.
Surface and Coatings Technology | Year: 2015

In this study, two types of blended alloys were processed by plasma transferred arc (PTA) hardfacing to form coatings. In the first case, a pre-alloyed Cu-Sn alloy and a pre-alloyed Co-base alloy were blended at a weight ratio of 85:15 (Cu-Sn/Co-base). In the second case, the pre-alloyed Cu-Sn and Co-base alloys were mixed with the molybdenum (Mo) element at a weight ratio of 81:15:4 (Cu-Sn/Co-base/Mo). Metastable liquid phase separation formed in the Cu-Sn/Co-base and Cu-Sn/Co-base/Mo coatings. The Co-rich spheroids as the minor precipitating alloy particles distributed on the Cu-rich matrix. The Co-rich spheroids consisted of α(Co) and M7C3 phases, and the Cu-rich matrix included α(Cu, Sn) and Cu10Sn3 phases. The relative content of α(Co)+M7C3 phases in the Cu-Sn/Co-base/Mo coating was higher than that in the Cu-Sn/Co-base coating. The numbers of the Co-rich spheroids in the cross section of the Cu-Sn/Co-base coating increased with increasing the distance from the substrate, and an obvious macroscopic segregation could be found in the coating close to its substrate. When Mo as additive was further added, the numbers of the Co-rich spheroids in the cross section of the coating increased and the macroscopic segregation could not be seen when compared to that in the Cu-Sn/Co-base coating. The wear rate of the Cu-Sn/Co-base and Cu-Sn/Co-base/Mo coatings was lower than that of the Cu-Sn coating, and a distinct improvement of the wear rate could be obtained in the Cu-Su/Co-base/Mo coating, attributing to mainly the increasing hardness of the coatings by sequence of the Cu-Sn coating, Cu-Sn/Co-base coating, and Cu-Sn/Co-base/Mo coating. The friction coefficient of the coatings has an increasing trend by sequence of the Cu-Sn coating, Cu-Sn/Co-base coating, and Cu-Sn/Co-base/Mo coating, but an obvious difference could not be seen in the coatings. © 2014 Elsevier B.V.

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