Wenzhou Hongfeng Electrical Alloy Co.

Wenzhou, China

Wenzhou Hongfeng Electrical Alloy Co.

Wenzhou, China
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Wang P.,Shanghai Hiwave Advanced Materials Technology Co. | Liu W.,Shanghai Hiwave Advanced Materials Technology Co. | Chen L.,Shanghai Hiwave Advanced Materials Technology Co. | Mu C.,Wenzhou Hongfeng Electrical Alloy Co. | And 2 more authors.
RSC Advances | Year: 2015

As one of the most industrially important metals, copper (Cu) was successfully reinforced with graphite nanosheets (GNSs). A nacre-inspired laminated GNSs/Cu composite material was fabricated by a combination of ball-milling and hot-rolling techniques. During the ball-milling process, the GNSs were in situ produced from graphite exfoliation. The Cu-GNSs composite ingot was hot-rolled into a belt to form a laminated structure. The laminated Cu-GNSs composite material showed improved mechanical properties observed from tensile and three-point bending tests. The Young's modulus of Cu-GNSs composites was up to 170 GPa and the bending strength reached 660 MPa. This processing route was also advantageous in low-cost, mass-producing manufacture. © The Royal Society of Chemistry 2015.


Jiang W.,Shanghai JiaoTong University | Zhao C.-L.,Beijing University of Posts and Telecommunications | Li S.-H.,Shanghai JiaoTong University | Chen L.,Wenzhou Hongfeng Electrical Alloy Co.
Neurocomputing | Year: 2014

Detecting spatiotemporal pattern from noisy sequences of events plays a very important role in presence sharing, Internet of Things (IoT) and many other fields. As pointed out in existing literature, the core activities of these applications involve event notifications. However, excessive number of event notifications will lead to user's intolerability. Existing literature proposed a Spatiotemporal Pattern Learning Automata (STPLA) to solve this problem effectively in both stationary and non-stationary environments. However, one limitation of the STPLA is that it cannot be both memory balanced and bias toward any of the two actions, i.e., "suppress" or "notify". To solve this problem, this paper proposed a new Learning Automata based approach, named as Spatiotemporal Tunable Fixed Structured Learning Automata (STP-TFSLA), for online tracking of event pattern. Furthermore, we also show that the STP-TFSLA is with small memory footprint and is able to cope with non-stationary environment. © 2014 Published by Elsevier B.V.


Wang L.,Shanghai Hewu New Material Technology Ltd. | Liu W.-L.,Shanghai Hewu New Material Technology Ltd. | Chen L.-S.,Wenzhou Hongfeng Electrical Alloy Co.
Applied Mechanics and Materials | Year: 2013

The paper analyzes the influence of structural parameters on the electrical performance of the microstructured environmentally-friendly electrical contact material Ag/SnO2 by using numerical simulation method. The numerical results show that the reisitivity of fiber-like electrical contact material Ag/SnO2 is significantly reduced compared with the resistivity of Ag/SnO2 adding reinforcing nanoparticles in the traditional way. So the fiber-like electrical contact material Ag/SnO2 exhibits higher conductivity in macro. On further analysis, we learn that the resistivity of fibrous electrical contact materials is related to weight percent of reinforced phase, and micro-structural parameter of length to diameter ratio. The resistivity increases as weight percent of reinforced phase increases, and decreases non-linearly with micro-structural parameter of length to diameter ratio increasing. This demonstrates that numerical simulation is one of effective methods for analysis of the electrical performance of the microstructured electrical contact material. © (2013) Trans Tech Publications, Switzerland.


In the present invention, a method of preparing Ag-based oxide contact materials with directionally arranged reinforcing particles is disclosed, comprising steps of: a) preparing evenly dispersed composite powders by chemical co-precipitation method combining with roasting, b) granulating the composite powders by high energy ball milling, and sieving the powders, c) mixing the powders and Ag matrix in a powder mixing machine, d) cold isostatic pressing, e) sintering, f) hot-pressing, g) hot-extruding to obtain Ag-based oxide contact materials with directionally arranged reinforcing particles. This method can obtain particle reinforced Ag-based material with good electrical performance even when the reinforced (oxide) particles are very small. This method is simple, easy to operate, and does not require special equipment. The resistance to welding and arc erosion, electric conductivity and the processability of the material prepared through this present invention can be greatly improved.


Patent
Wenzhou Hongfeng Electrical Alloy Co. | Date: 2012-12-26

A method of preparing silver-based oxide electrical contact materials with fiber-like arrangement, includes the following steps of: (1) uniformly mixing the silver-metal alloy powders and graphite powders and then ball-milling; (2) internally oxidizing the ball-milled powders; (3) sieving; (4) placing the sieved powders and the matrix powders into the powder mixer for mixing; (5) cold-isostatically pressing; (6) sintering; (7) hot-pressing; and (8) hot-extruding, thereby obtaining the silver-based oxide electrical contact material with fiber-like arrangement. The method of the present invention can obtain the silver-based oxide electrical contact material having neat fiber-like arrangement with no specific requirement on processing deformation, plasticity and ductility of the reinforcing phase. The production process in this method is simple and is easy to operate. Besides, there is no particular requirement on the equipment. The method greatly improves the performance of contact materials in aspects of resistance to welding and arc erosion, conductivity, and processing performance.


Patent
Wenzhou Hongfeng Electrical Alloy Co. | Date: 2012-12-26

A method for preparing silver-based electrical contact materials with fiber-like arrangement of reinforcing nanoparticles includes (1) uniformly mixing reinforcement powders and silver matrix powders for ball milling; (2) pouring the obtained composite powders and silver matrix powders into a powder mixing machine for powder mixing; (3) cold isostatic pressing; (4) sintering; (5) hot pressing; and (6) hot extruding to obtain silver-based electrical contact materials with fiber-like arrangement of reinforcing nanoparticles. The method of the present invention can obtain silver-based electrical contact materials with fiber-like arrangement of reinforcing nanoparticles with no specific requirement on processing deformation, and the plasticity and ductility of the reinforcing phase. Furthermore, it has simple processes, low cost and no particular requirements on the equipment. Contact materials prepared by the present method have good resistance to welding and arc erosion, conductivity and a greatly enhanced processing performance.


Patent
Wenzhou Hongfeng Electrical Alloy Co. | Date: 2013-03-21

A preparation method of an electrical contact material includes steps of: adopting chemical plating to cover nickel coating on aquadag or metallic oxide, then covering with silver coating, and forming AgNiC or AgNiMeO core-shell structure, which improves interface wettability of aquadag, metallic oxide and silver matrix, and removes the adverse effect on the electrical contact material mechanical property due to bad interface wettability in conventional powder metallurgy method. What is important is that the silver in intermediate composite particles is replaced by nickel coating, thus reduce the silver use level. The main function of silver coating is to improve inoxidizability of composite particles, sintering granulation property and the deformability during the manufacturing process of intermediate composite particles, thus improve the technological property.


A method of preparing silver-based electrical contact materials with directionally arranged reinforcing particles includes steps of: (1) preparing composite powders with Ag coating on the reinforcing phase by chemical plating coating; (2) granulating; (3) placing the granulated powders and the matrix silver powders into the powder mixer for mixing; (4) cold-isostatically pressing; (5) sintering; (6) hot-pressing; (7) hot-extruding, thereby obtaining the reinforcing silver-based electrical contact materials with directionally arranged particles. Regardless of the size of reinforcing particles, the present invention can obtain particle-reinforced silver-based materials with excellent electrical performance. The process is simple and easy to operate, and places no special requirements on the equipment. Furthermore, the resistance to welding and arc erosion, and the conductivity of the material prepared by the present invention can be greatly improved. Moreover, the processing performance is excellent.


Patent
Wenzhou Hongfeng Electrical Alloy Co. | Date: 2012-12-26

In the present invention, a method of preparing Ag-based oxide contact materials with directionally arranged reinforcing particles is disclosed, comprising steps of: a) preparing evenly dispersed composite powders by chemical co-precipitation method combining with roasting, b) granulating the composite powders by high energy ball milling, and sieving the powders, c) mixing the powders and Ag matrix in a powder mixing machine, d) cold isostatic pressing, e) sintering, f) hot-pressing, g) hot-extruding to obtain Ag-based oxide contact materials with directionally arranged reinforcing particles. This method can obtain particle reinforced Ag-based material with good electrical performance even when the reinforced (oxide) particles are very small. This method is simple, easy to operate, and does not require special equipment. The resistance to welding and arc erosion, electric conductivity and the processability of the material prepared through this present invention can be greatly improved.


Patent
Wenzhou Hongfeng Electrical Alloy Co. | Date: 2015-09-02

This invention discloses a preparation method of electrical contact material. The procedure: this invention adopts chemical plating to cover nickel coating on aquadag or metallic oxide, then cover with silver coating, forming Ag-Ni-C or Ag-Ni-MeO core-shell structure, which improves interface wettability of aquadag, metallic oxide and silver matrix, and removes the adverse effect on electrical contact material mechanical property due to bad interface wettability in conventional powder metallurgy method. What is important is that the silver in intermediate composite particles is replaced by nickel coating, thus reduce the silver use level. The main function of silver coating is to improve inoxidizability of composite particles, sintering granulation property and the deformability during the manufacturing process of intermediate composite particles, thus improve the technological property.

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