Properties of tungsten wire in powder metallurgical processing with ultrafine powder

Abstract

The paper presents the results of the investigation of properties of the tungsten wire obtained from powders with particle sizes from 1 to 5 μm with the addition of ultrafine powders with particle sizes of less than 0.5 μm produced by the reduction of hydrogen plasma at a high temperature. Different compositions of mixtures were studied and a new optimal composition was developed. Methods of its compressing and presintering of bars were also developed. The results showed that mechanical and performance properties of the wire with a new composition have higher stability compared to the properties of the wire obtained by the standard technology. They allowed:

– to lower the creep for the wire with the diameter of 1250 μm,

– to achieve a stapel structure for the wire with the diameter of 650–1450 μm;

– to improve the spiralability of the wire;

– to increase the good-to-bad yield to 3.79 % for the wire with the diameter of 120 μm.