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Wang C.P.,Xiamen University | Lin L.C.,Xiamen University | Xu L.S.,Xiamen University of Technology | Xu W.W.,Xiamen University | And 3 more authors.
International Journal of Refractory Metals and Hard Materials | Year: 2013

A novel W-skeleton sintering process was introduced by adding blue tungsten oxide (BTO). The effect of BTO on skeleton sintering and infiltration of W-Cu composites was investigated. The microstructural study, analyses of thermal diffusivity, as well as copper- and oxygen concentration of W-Cu composites were carried out using a combination of scanning electron microscopy (SEM), laser flash method and chemical composition analysis respectively. The results indicate that the addition of BTO can increase the porosity of the W-skeleton. As a consequence, copper concentration can be increased in W-Cu composites. The other beneficial effect is the formation of an open pore structure with the addition of BTO. The relative density is higher than 99% for W-25Cu composites with the addition of BTO and the corresponding theoretical thermal conductivity is 231 W/(m K). Furthermore, the BTO addition does not result in any increase of oxygen content of the W-skeleton. © 2013 Elsevier Ltd. All rights reserved.


Lv Y.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Song J.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Lian Y.,Southwestern Institute of Physics | Yu Y.,Xiamen Honglu Tungsten Molybdenum Industry Co. | And 2 more authors.
Journal of Nuclear Materials | Year: 2015

The ultra-high purity (>99.9999 wt.%) and fully dense (19.23 g/cm3) tungsten (W) by chemical vapor deposition (CVD) was prepared with the deposition rate higher than 0.6 mm/h. The thermal diffusivity, specific heat, heat conductivity and coefficient of thermal expansion of CVD-W at the temperature range of 473-1273 K were measured. Thermal shock tests were carried out on a 60 kW electron-beam material testing scenario to investigate the crack-resistant performance of CVD-W, and the crack initiation threshold energies of CVD-W were achieved in 5 ms heating duration. Compared to forged-W, the higher heat conductivity (160.5-111 W/(m K)) and threshold energy of crack initiation (1.1-1.65 MJ/m2) of CVD-W can be attributed to the material characteristics including high purity, fully dense, rough surface composed of pyramid-like grains, and the columnar grain structures. © 2014 Elsevier B.V. All rights reserved.


Song J.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Yu Y.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Zhuang Z.,Xiamen Tungsten Co. | Lian Y.,Southwestern Institute of Physics | And 2 more authors.
Journal of Nuclear Materials | Year: 2013

W-Cu functionally graded materials (FGMs) are designed to be a transition layer between CuCrZr bulk material and a W surface layer in plasma-facing components. In this study, a type of in-house developed ultrafine W-Cu composite powder has been used to fabricate a W-Cu FGM, which consists of three layers of W-10Cu, W-32Cu, and W-60Cu respectively. The sintered FGM has a homogeneous microstructure and a residual porosity of less than 3.3%. The W-10Cu side of the FGM has been coated with pure W using an optimized chemical vapor deposition (CVD) process with an increased deposition rate of 0.8 mm/h. The thickness of the coating is around 2 mm and the density is as high as 19.23 g/cm3. The columnar grain size of CVD-W at the end of deposition is approximately 20-50 μm in the direction parallel to the substrate and 1-1.5 mm in the direction perpendicular to the substrate. Compared with plasma-sprayed W-Cu FGM and W coating, the FGM and CVD-W developed in this study have a better microstructure, which is important for the thermal and physical properties of the components. © 2013 Elsevier B.V. All rights reserved.


Sun B.,Northeastern University China | Song J.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Yu Y.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Zhuang Z.,Xiamen Tungsten Co. | And 4 more authors.
International Journal of Refractory Metals and Hard Materials | Year: 2014

Tungsten-copper (W-Cu) composites containing 10 wt.% Cu (W-10Cu) were prepared by pressing and sintering a type of ultrafine composite powder. Constituent phases, grain size and orientation relationship between W and Cu grains were characterized and investigated. The results show that W-10Cu composites are composed of W and Cu elementary substance and orientation relationship between W and Cu grains is defined as 1̄1̄4Cu/ /01̄1W and (131)Cu//(200)W. The existence of the orientation relationship depends largely on the two factors. First, the grain sizes of both W and Cu were in the nanoscale range. Secondly, the interplanar spacing between both phases can match well owing to the residual stress of the W/Cu interface. Consequently, the obtained composites exhibited high density and excellent thermal conductivity. © 2014 Elsevier Ltd.


Zhao X.M.,Northeastern University China | Song J.P.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Yu Y.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Zhuang Z.G.,Xiamen Tungsten Co. | And 2 more authors.
International Journal of Refractory Metals and Hard Materials | Year: 2016

This work deals with the effects of thermal fatigue testing on the surface topography of W coatings on graphite substrate with Si intermediate layers, where W coatings were deposited by chemical vapor deposition (CVD-W coatings) and Si intermediate layers were prepared by physical vapor deposition (PVD-Si layers). The surface topography of samples both as-deposited and after thermal fatigue testing were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Comparative studies show that CVD-W coatings have so excellent thermal conductivity that electronic beams are only absorbed by a thin layer on the coating surface. The absorbed thermal loads give rise to the melting of the pyramid-like W grain tips and the formation of shallow melting pools. Meanwhile, the size of the recrystallized grains on the surface is much smaller than those of the initial grains after cooling. Since the fine recrystallized grains can undoubtedly suppress the crack propagation, no visible failure was found in sample after thermal fatigue testing. © 2016 Elsevier Ltd. All rights reserved.


Xu Y.,CAS Hefei Institutes of Physical Science | Xie C.Y.,CAS Hefei Institutes of Physical Science | Qin S.G.,Advanced Technology and Materials Co. | Song J.P.,Xiamen Honglu Tungsten Molybdenum Industry Co. | And 6 more authors.
Physica Scripta | Year: 2014

To upgrade the Experimental Advanced Superconducting Tokamak dome and first-wall, flat-type W/Cu plasma-facing components will be installed in the coming years in order to exhaust the increasing heat flux. Mock-ups with an interlayer of oxygen-free Cu (OFC) made by vacuum hot pressing have been developed and the bonding strength was found to be over 100 MPa. The behavior of the mock-ups under steady-state high heat flux loads has been studied. No crack or exfoliation occurred on the W surface and W/OFC/CuCrZr interfaces after screening tests with heat fluxes of 2.24-7.73 MW m-2. The mock-up survived up to 1000 cycles heat load of 3.24 MW m-2 with cooling water of 4 m s-1, 20 °C. However, cracks appeared in W around the gaps at about the 300th cycle under a heat load of 5.37 MW m-2. We have also studied the chemical vapor deposition W coated CuCrZr with an OFC interlayer. It has been found that: (i) the OFC interlayer plays a significant role in achieving coatings without any crack, (ii) the deposition rate was about 0.3-0.5 mm h-1 at 490-580 °C and (iii) a bonding strength of 53.7 MPa was achieved with laser surfi-sculpt. © 2014 The Royal Swedish Academy of Sciences.


Mamen B.,CNRS Femto ST Institute | Song J.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Barriere T.,CNRS Femto ST Institute | Gelin J.-C.,CNRS Femto ST Institute
Powder Technology | Year: 2015

The sintering behaviour of metal injection moulded tungsten components using fine (FSSS 0.4 to 1 μm) and coarse (FSSS 5.0 to 7.0 μm) powder has been investigated via dilatometric and three-point bending tests in a Setaram© analyser under a pure hydrogen atmosphere at temperatures up to 1700 °C. The experimental results have been applied to determine the material parameters in the viscoplastic constitutive law for continuum sintering model, which has been implemented in a finite element code ABAQUS software via the user subroutine UMAT for predicting the final shrinkage and density distribution of the sintered components. The effect of particle size of the powder on the densification behaviour, sintering activation energy, and sintering stress has been analysed. © 2014 Elsevier B.V.


Song J.,University of Franche Comte | Song J.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Barriere T.,University of Franche Comte | Liu B.,Southwest Jiaotong University | And 2 more authors.
Powder Metallurgy | Year: 2010

The sintering behaviours of injection moulded components in 316L stainless steel powder are investigated by means of the bending and dilatometric tests in the furnace. Various thermal cycles are realised for different tests. The experimental results are used to determine the parameters of uniaxial viscosity and sintering stress in the viscoplastic constitutive law, which is important for description of the sintering behaviours. The sintering models are implemented into the finite element solver, incorporated with the identified parameters, to simulate the size change and shape distortion of powder injection moulded components during the sintering process. The sintering simulation takes into account the green inhomogeneity caused by powder binder segregation in the previous injection process. The simulation results for the sintering process of a three-dimensional wheel component are compared with the experimental ones. It proved validity of the sintering model and the approaches for parameter determination proposed in the study. © 2010 Maney Publishing.


Yu Y.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Song J.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Bai F.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Zheng A.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Peng F.,Xiamen Honglu Tungsten Molybdenum Industry Co.
International Journal of Refractory Metals and Hard Materials | Year: 2015

High purity (> 99.999 wt.%, 5N) or ultra-high purity (> 99.9999 wt.%, 6N) tungsten (W) electrodes are vital to the performance and lifetime of high intensity discharge (HID) lamps. On the other hand, alloys based on high purity (> 99.99 wt.% or 99.995 wt.%, 4N or 4N5) W are used as sputtering targets to deposit the films in semiconductor devices. In this study, a highly efficient and cost-saving method for mass producing 6N W powder has been developed. The 5N and 6N W rods and wires for the electrodes of HID lamps have been manufactured by using this powder. In addition, vacuum hot pressing has been employed to prepare 4N5 tungsten-titanium (W-Ti) and 4N tungsten-silicon (W-Si) sputtering targets successfully. The impurities and microstructures of the developed high purity W products have been investigated and are suitable for lighting, semiconductor and photovoltaic applications. © 2015 Elsevier Ltd. All rights reserved.


Yu Y.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Bai F.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Zheng A.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Song J.,Xiamen Honglu Tungsten Molybdenum Industry Co. | Peng F.,Xiamen Honglu Tungsten Molybdenum Industry Co.
Advances in Tungsten, Refractory and Hardmaterials IX - Proceedings of the 9th International Conference on Tungsten, Refractory and Hardmaterials | Year: 2014

High purity (>99.999 w/o, 5N) or ultra-high purity (>99.9999 w/o, 6N) tungsten (W) are the vital electrode materials in high intensity discharge (HID) lamps due to its function on increasing the performance and lifetime of lamps. On the other hand, high purity W alloys (>99.99% or 99.995%, 4N or 4N5) are used as the sputtering targets to deposit the films in semiconductor device fabrication. In this study, a high efficient and cost-saving method for mass producing 6N W powder has been developed. The 5N and 6N W rods and wires for the electrodes of HID lamps have been manufactured by using this powder. In addition, vacuum hot pressing has been employed to prepare 4N5 tungsten-titanium (W-Ti) and 4N tungsten-silicon (W-Si) sputtering targets successfully. The impurities and microstructures of the developed high purity W products have been investigated.

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