Tungsten Copper Electrode by Thermo-chemical Process

Some new technology has gradually developed, which has more practical and operational effects are:

4. Injection molding: the process is suitable for the manufacturing of parts with complex structure and a smaller volume, which prepared a uniform structure, precise size, but the control of process parameters is more complex, and higher production cost of the mold;

5. Coated powder process: based on Cu cladded by W powder, which will be an oxide, a compound or compound solution both doped together, dried calcined powder coated after the reduction.

In addition, vacuum sintering, microwave sintering, activated sintering, plasma arc welding sintering process all have own advantages and application scope. Here we mainly introduce the coated powder process by thermal chemical method.

Take tungsten copper W-25Cu electrode as example, raw materials for the tungsten trioxide and copper oxide, both of the powders were uniformly mixed by a certain percentage, sieved and calcined in the calciner 2h, coated powder obtained after the reduction. Finally, under a certain pressure is press-molded and sintered to send a muffle furnace. In the process of detecting, the density measured by Archimedes method; alloy powder and fracture morphology was observed with a scanning electron microscope; tensile strength measured; the electrical conductivity measured by bridge method; use the X-ray spectrum analyze its composition; particle size distribution by laser transmission.

In the process of calcination, the two oxides react chemically, W and Cu atoms in atomic cooperation with key generation copper tungstate (CuWO4). From the microscopic point of view, Cu restored deposit with W atom, and form tungsten copper-clad with fine grains, which has close particle size. The surface of the fine particles can be conducted to promote densification. Judging from the fracture surface, compared with tungsten copper electrode by other processes only intergranular fracture phenomenon, its natural tensile fracture showed significant transgranular fracture phenomenon. This is due to the particle surface tungsten powder sintering occurs when welded to each other and rearranged, and the more complete crystallization, thereby forming a solid tungsten skeleton with network , which greatly enhance the structural strength of tungsten copper alloy electrodes inside the organization. For tungsten copper electrode, tensile strength or flexural strength and electrical conductivity are two important characterizations. Tungsten copper-clad composite powder compacts during sintering may be uniform tungsten and copper two-phase distribution, and uniform organization facilitates the electrified process effectively increase conduction average speed of electrons, thereby significantly enhanced conductivity of tungsten copper electrodes performance.

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