Metals
·
2017
·Vol. 7
·期 4
·137
·
IF 1.984
Xiaobo Wang,Taoyuan Ouyang,Xiaohua Duan,Chengzhu Ke,Xuemin Zhang,Jie Min,Aang Li,Weiyang Guo,Xudong Cheng
One type of multimodal (comprised of nanometer and sub-micrometer WC particles) and two types of conventional (comprised of nanometer and sub-micrometer WC particles, respectively) WC/Co powders were deposited on AISI 304L stainless steel substrates by using high velocity oxygen fuel spraying. The use of multimodal WC particles was indicated to have a beneficial effect on the solar absorptance (α) of the WC/Co coatings. The α of the multimodal WC coating reached 0.87, which was much higher than what can be achieved by either fine (0.82) or coarse powders (0.80) alone. By microstructural analysis, the enhancement in solar absorptance of the multimodal WC/Co coating was ascribed to the layer of distributed WC particles. During the thermal spraying, the nanostructured WC particles underwent rapid melting for the large specific surface area while the aggregated powders were heated, but not necessarily melted. The molten nano-WC would fill the available pores between the softened and heated aggregates, providing a layered distribution of WC particles for the spray-deposited coating. In this condition, the light-trapping in the multimodal coating will be enhanced due to the efficient light reflection among the multimodal WC particles, which contributes to the enhancement of solar absorptance.Keywords:solar selective absorbing coating;high velocity oxygen fuel;selective absorbing properties
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yingxuan Chen,Hongzhi Cui,Leigang Li,Xiaojie Song,Yipan Feng,Cuiting Zhang,Wei Huang
Benefiting from the extraordinary mechanical properties especially at elevated temperatures, Ni625/WC composites have been regarded as promising structural materials for deep well drilling. However, the addition and formation methods of WC would effect the mechanical properties of the composites greatly. In this work, Ni625/WC composites by spark plasma sintering technique are investigated, and the influences of WC by the external adding method and the internal in-situ formation method on the morphology, friction and fracture behaviors of the materials are analyzed systematically. It is found that the samples with externally added WC as the reinforcing phase possess enhanced wear resistance because of the high hardness and embedding depth of the externally added large-size WC. The large hardness difference with the matrix and the high brittleness lead to serious adhesive wear and poor toughness of the samples. On the contrary, the samples with in-situ WC as the reinforcing phase have superior toughness owing to the tighter bonding of in-situ generated WC to the matrix, lower brittleness of tungsten carbide and slower propagation of cracks. This work, with the systematic and comparative study of the incorporation of WC to the influence of mechanical properties of Ni625/WC, would enlighten the design of advanced metal-ceramic composites to meet the specific requirements of different structural materials.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2024
·
IF 5.3
Zhaoyang Zheng,Dong Han,Tianyu Zhang,An Du,Ruina Ma,Yongzhe Fan,Xue Zhao,Xiaoming Cao
The Co-depletion zone in WC–Co brazed joints is the main zone of joint failure, so it is crucial to explore novel processes to inhibit the Co-depletion zone and enhance the joint shear strength. In this study, a composite process of pre-plating Cu on the WC–Co surface + brazing was designed. Co-depletion zone reduces from 6 μm to 1 μm due to the Cu plating. Meanwhile, the formation of a plating fusion zone in the filler layer transforms TiCo with a thickness of 2.5 μm into a small number of TiCo particles. Moreover, the high concentration of Cu atoms in the vicinity of the WC particles at the interface changes the Co-segregation layer in the WC into a Cu-rich layer. The concentration of Cu in the filler layer leading to precipitation of TiCu and Ti 2 Cu particles. Ti 2 Cu particles encapsulated by ductile Ag–Cu–In ternary eutectic contribute to inhibit the cracks propagation. The shear strength of the joints was enhanced by 51.3 % to 295 MPa. The composite process of pre-plating on the base material surface + brazing has positive significance in inhibiting the excessive diffusion of elements from the base materials to the filler layer.
研究领域:
材料科学
·
冶金学
·
焊接工程
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产品关联
DOI
高影响因子
Coatings
·
2023
·Vol. 13
·期 7
·1246
·
IF 3.4
Wenjuan Qi,Desheng Ding,Weijie Luo,Weiliang Jin,Qian Kou,Chuntao Ge,Saijun Xiao
The hardness and wear resistance of amorphous Al–Mn alloy coatings can be improved by incorporating ceramic particles into them to extend their application. In this paper, Al–Mn/WC composite coatings have been prepared with electrodeposition in stirred AlCl3–NaCl–KCl–MnCl2molten salts at 180 °C with the addition of WC particles. The effects of stirring speed (400–700 rpm) and cathode current density (15–75 mA/cm2) on the produced Al–Mn/WC composite coatings have been studied. At 600 rpm and 700 rpm, the Al–Mn/WC composite coatings exhibited the best uniform distribution of the embedded WC particles, with the tested microhardness value up to 650 HV0.1, compared with 530 HV0.1of the Al–Mn alloy. Moreover, under various cathode current densities, the best quality of the Al–Mn/WC composite coating was obtained at 55 mA/cm2, with a homogeneous distribution of WC particles and the highest microhardness value (670 HV0.1). It is expected that this method could be extended to be applied for the preparation of aluminum-based and magnesium-based ceramic composite coatings.Keywords:AlCl3–NaCl–KCl–MnCl2molten salts;electrodeposition;WC particles;Al–Mn/WC composite coating
研究领域:
材料科学
·
表面工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Rengui He,Jianying Wang,Meng He,Hailin Yang,Jianming Ruan
Composite powder of tungsten carbide with nano-cobalt coatings was successful manufactured via a novel sol-gel process, and coarse grained WC-4 wt% Co cemented carbide was produced from the cobalt-coated WC powder. Phase composition and microstructure evaluation were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results revealed that the WC particles were completely encased in the CoC 2 O 4 layers by the sol-gel process. Core-shell structured WC-4 wt% Co composite powder was subsequently prepared by reducing the WC-CoC 2 O 4 precursor powder in hydrogen atmosphere. The morphology and crystal structure of the cobalt-coating were found to depend on the reduction temperature. Chemical analyses revealed that the WC-Co composite powders were non-contaminated and composition-controllable. WC-4 wt% Co cemented carbide fabricated from the cobalt-coated WC composite powder showed a refined and uniform microstructure, and therefore improved mechanical properties , compared to the cemented carbide made by ball-milled WC-Co powder. The transverse rupture strength was 2249 MPa in the cemented carbide from the cobalt-coated WC powder, compared to 1871 MPa of the carbide made by the ball-milling powder.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2024
·
IF 3.7
Huijun Shang,Hengli Li,Weijun Li,Feng Pan,Zhan Du
In this paper, the effects of reaction parameters on the deep-reduction and carbonization process of WO 2 -Co to WC-Co were studied. The results indicate that oxygen loss rate of WO 2 is positively correlated with temperature and methane partial pressure. The partial pressure of methane has no significant effect on the formation rate of WC. The carbon content and particle size of the product increase with the increase of CH 4 partial pressure. By synergistically regulating the reaction temperature to 950 °C, methane partial pressure to 1.25%, and reaction time to 60 min, ultrafine WC-Co powder without η phase can be obtained. The particle size of the composite powder is 128 nm, with total carbon content of 6.16%, free carbon content of 0.4%, and residual oxygen content of 0.05%, respectively. The growth rate relationship of tungsten carbide is as follows:
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Xiao-Hui Yang,Kai-Fei Wang,Kuo-Chih Chou,Guo-Hua Zhang
Fine grained WC-Co-Ni cemented carbides with a low binder content have been successful manufactured via the powder metallurgy method. The WC-Co-Ni composite powder with homogeneous distributions of Co and Ni was synthesized by chemical co-precipitation with the raw materials of WC powder, oxalic acid and chlorides of Co and Ni. In this study, the effects of cobalt and nickel contents on the properties of cemented carbides were investigated systematically. The experimental results demonstrated that the alloy prepared by vacuum sintering had uniform grain size distribution and no abnormal growth of WC grains. When the cobalt content was 4 wt% and 5 wt%, the obtained composites almost completely consolidated with excellent hardness and fracture toughness. Among them, for the sample WC-4 wt%Co, the relative density could reach 99.37%, and the Vickers hardness and fracture toughness were 2010 HV 30 and 8.55 MPa·m 1/2 , respectively. When Ni was added to replace part of Co, the relative density of WC-Co-Ni decreased and the fracture toughness was improved without basically sacrificing the hardness. For the sample WC-2 wt%Co-2 wt%Ni, the hardness decreased to 1921 HV 30 , while the fracture toughness increased to 8.97 MPa·m 1/2 .
研究领域:
材料科学
·
粉末冶金
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Jixue Zhou,Guochen Zhao,Jinshang Li,Jie Chen,Suqing Zhang,Jin Wang,Frank C. Walsh,Shuncai Wang,Yanpeng Xue
Weak hierarchical rough structures on superhydrophobic surfaces hinder their practical industrial applications. This paper reports a strategy to fabricate robust nickel-based superhydrophobic coatings via the codeposition of nanosized WS 2 and WC particles. The Ni/WC/WS 2 composite coatings were synthesized on mild steel substrates by one-pot electroplating followed by the adsorption of stearic acid self-assembled monolayers to modify the surface wetting. The particle concentration in the bath was investigated and the maximum water contact angle of approx. 170° was achieved by optimizing the particle contained. Hardened by WC and lubricated by WS 2 inclusions the superhydrophobic coatings showed remarkable abrasive resistance with a bearing capacity ≥10,000 mm abrasion length. The coatings also showed aerophilic behavior and good environmental stability over >6 months.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE AND TECHNOLOGY
·
2023
·
IF 1.8
Hong Zeng,Wenbin Liu,Feitong Han,Chongbin Wei
Here, the effects of Ru and ball-milling on the mechanical properties of WC–10Co-cemented carbide were investigated using systematic characterisation and microstructure analysis. It was found that with an increase in the Ru content, the WC grain morphology and grain size did not change; however, the values of density and coercivity, Co magnetism, hardness, and fracture toughness of cemented carbide were changed. When the Ru content was 4%, compared with the alloy without Ru, the toughness increased from 16.8 to 24.2 (MPa. m1/2) and the hardness increased from 1290 to 1330 (HV30). Meanwhile, the analysis of the mixing process shows that the optimal ball-milling time is determined by the performance combination of the obtained alloy.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2022
·
IF 4.804
Jiakun Wu,Haikuo Wang,Zhicai Zhang,Chao Wang,Zhiqiang Hou,Shun Wan,Dazhuan Wu,Xiaoping Ouyang
WC-cBN-MoS 2 self-lubricating ceramics were synthesized by using high pressure and high temperature sintering method. An analytical model of the self-lubricating properties has been developed to reveal the interrelationship between mechanical and self-lubricating properties. The influence of mechanical and self-lubricating properties of ceramics on the wear rate were analyzed. Self-lubricating performance optimization criterion are proposed accordingly. It was found that MoC, WS 2 can be formed during sintering, which can ensure self-lubricating and low temperature sintering properties. Adhesive wear is the main wear mechanism, the extent of which varies with the content of self-lubricating components. The high modulus of elasticity is the main reason for the excellent self-lubricating and mechanical properties of composites. The well-sintered WC-cBN-MoS 2 bulks present an excellent self-lubricating property with a hardness of 26.3 GPa and fracture toughness of 10.5 MPa·m 1/2 , which is improved at least by 52% and 46% respectively compared with the traditional self-lubricating ceramics.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
POWDER METALLURGY
·
2025
·
IF 1.8
Xiao-Chun Deng,Guo-Hua Zhang
In this work, the ultra-fine grain WC-10Co alloys were prepared through a two-step sintering process comprising steps of low-temperature sintering for a long time and high-temperature sintering for a short time. The effects of sintering methods (one-step/two-step sintering) on the microstructure, density, grain size and performance of WC-10Co hard metals with or without VC addition were investigated. The densities of all samples were lower than 97.0% in one-step sintering. After two-step sintering, the relative densities of all samples were increased, and those of the samples without VC were higher than 98.5%. In addition, there are a large number of grains with a high aspect ratio in the samples without VC. The pure WC-10Co alloy showed the best comprehensive mechanical properties after long-time (2 hours) sintering at a low temperature (1300 °C) and short-time (10 minutes) sintering at a high temperature (1450 °C), and the grain size, hardness and toughness of the sample were 0.70 μm, 15.35 GPa and 13.54 MPa·m1/2, respectively. The grain size of the sample containing 0.5 wt.% VC was only 0.26 μm under the same sintering conditions, which showed a high hardness of 18.14 GPa and a toughness of 8.56 MPa·m1/2.
研究领域:
材料科学
·
金属学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2023
·
IF 3.6
Dongyang He,Hailang Liu,Zhuangzhi Wu,Dezhi Wang
The low ductility of refractory Mo-based materials limits their further processing and wide applications. To address this challenge, a composite strengthening and toughening strategy was proposed by the simultaneous addition of WC and La 2 O 3 . And a collaborative improvement of strength and ductility is achieved over the as-sintered Mo-WC-La 2 O 3 , exhibiting a total elongation (TE) of 33.63% and an ultimate tensile strength (UTS) of 611.33 MPa, about 50.27% and 24.76% larger than those of pure Mo, respectively. Furthermore, the corresponding microstructural features and tensile fracture behavior were also discussed to explore the improvement mechanism. And it is found that the enhancement should be attributed to the high relative density, grain refinement, generated substructures and secondary phase particle refinement. Moreover, the additional toughening mechanisms of crack deflection, particles pull-out and crack halt can also prevent crack extension, which helps to give full play to the potential ductility of Mo composites. This work provides a new pathway for manufacturing advanced Mo-based products with excellent strength-ductility balance.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）