Views:4 Author:Site Editor Publish Time: 2021-02-22 Origin:Site
The improvement of the performance of tungsten-copper alloy is a concern of modern manufacturers. The alloy is a uniformly mixed structure of two-phase monomers of tungsten and copper. It is neither miscible nor intermetallic. It is a typical pseudo alloy. Modern production needs to obtain higher performance and denser tungsten-copper composite materials, it is necessary to overcome the mutual insolubility of tungsten and copper, and combine the characteristics of tungsten-copper composite products to perform compact pressure processing to improve compactness and comprehensive performance , To meet the requirements of modern production.
At present, there are two main methods to improve the properties of tungsten-copper alloys. One is to prepare ultrafine tungsten-copper powder, and the other is to improve the pressure-density process of tungsten-copper composite materials.
1.0 Preparation of tungsten copper ultrafine raw powder
There are six main preparation methods of ultrafine tungsten-copper composite raw powder, including mechanical alloying, sol-gel method, spray drying method, oxide co-reduction method, mechanical-thermochemical synthesis method and precipitation method.
1.1 Mechanical alloying is to put the raw material powder of tungsten and copper into a high-performance ball mill for ball milling, and control the time and speed to obtain refined raw material powder;
1.2 The tungsten copper composite powder prepared by the sol-gel method has uniform particle size, high purity, large surface activity, and is easy to prepare and shape;
1.3 The spray drying method can only obtain tungsten and copper oxide powder, and the reduction method can obtain ultrafine tungsten copper composite powder;
1.4 Oxide co-reduction method, tungsten and copper oxides are easier to mix and distribute than elemental metals, and the fully dispersed tungsten and copper oxides are reduced to obtain ultra-fine and uniform tungsten-copper composite powder;
1.5 The mechanical-thermochemical synthesis method uses tungsten and copper oxide powders to prepare powders by mechanical alloying and ball milling, and then uses the reduction method to obtain composite powders;
1.6 The precipitation method is to use the liquid phase to first precipitate the precipitate, and then subject to process conditions such as calcination and reduction to finally obtain the tungsten copper composite powder.
In actual production and application, multiple methods are often combined to obtain ultrafine tungsten copper composite raw powder to meet various production needs.
2.0 Improve the pressure densification process of tungsten copper composite materials
In order to further improve the compactness of the formed products of tungsten-copper composite materials, improve and improve their performance, according to the product variety, shape and other characteristics, pressure compaction processing is carried out on it. At present, the main pressure processing methods are: hot isostatic pressing, static Methods such as liquid extrusion and hot forging.
2.1 Hot isostatic pressing can eliminate defects such as voids and shrinkage holes in tungsten-copper composite materials. This process makes full use of the ductility of copper to improve the performance of the material, but this method has high equipment costs and low efficiency;
2.2 Hydrostatic extrusion is the use of a fluid medium to transmit force to the material, which is more conducive to the uniformity of deformation. This method can greatly improve the density, strength, and conductivity of the tungsten copper composite material;
2.3 Common deformation processes such as hot forging and hot rolling also improve the properties of tungsten copper composite materials.