Nano Tungsten-copper Rare Earth Composite Powder Preparation Process

Nano tungsten-copper composites have excellent properties of tungsten and copper, and are widely used in electrode materials, electrical contact materials, electronic packaging materials and heat sink materials. However, the disadvantages of immiscible tungsten and copper elements, large melting point difference, poor wettability and low density after sintering lead to the decrease of properties and the increase of production cost of tungsten-copper composites.

In view of the existing technical problems, some scholars have innovated a preparation method of nano-W-Cu-RE composite powders. The preparation of W-Cu composite powders by this method can improve the particle size, uniformity, compactness and comprehensive properties of materials, reduce production energy consumption and shorten production cycle. The main processes are as follows:

1)Soluble tungsten salt and soluble copper salt were selected as raw materials.

2)The solution of 20%-50% concentration was prepared by mixing raw materials with W:20%-80% mass ratio and Cu:20-80% mass ratio.

3)Adding acid solution to control step 2) The pH value of solution is 3-5;

4)After adding 0.01wt%-0.5wt% rare earth alloying elements, the saturated solution or near colloid can be obtained by stirring uniformly.

5)spray or dry the solution or near colloid according to known means to make the solvent evaporate quickly and produce near spherical precursor powder.

6)The precursor powders were calcined in high temperature fast decomposition furnace, and the precursor powders were decomposed rapidly to obtain W-Cu-REO composite powders.

7)Nano-sized W-Cu-RE composite powders were prepared by reducing W-Cu-RE oxide composite powders in a reducing atmosphere.

Rare earth elements Y, Ce, La and Gd refine grains by microalloying, which can effectively inhibit grain growth during calcination, high temperature reduction and sintering of powder products, and can preferentially adsorb impurity elements such as P and O to reduce impurity segregation. Rapid decomposition at high temperature avoids the phenomenon of copper concentration gradient, and can effectively and accurately achieve the predetermined ratio. Finally, the production cycle is short, energy consumption and copper loss are small, particle size, uniformity, compactness and comprehensive properties of materials are improved.

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