Development of feedstock of tungsten-nickel-iron- polyformaldehyde for MIM technology

Abstract

The article presents the results of the research and development of technology and formulation of the feedstock from domestic metal powders and polymers to fabricate complexshaped components from heavy alloy of VNZh 7-3 brand (90 wt. % tungsten - 7% nickel - 3% iron) by Metal Injection Molding (MIM technology). The metal part of the feedstock is composed of powders of tungsten, nickel and iron, and the polymer part is composed of polyformaldehyde with the addition of low-density polyethylene and beeswax. The modes of mixing the components and the influence of the composition of the feedstock on the melt flow rate and the homogeneity of the feedstock were investigated. The optimal formulation of the feedstock was determined. Microstructure, density and hardness of control samples fabricated by MIM technology from the developed feedstock, correspond to, and in some respects are superior to the samples of VNZh 7-3 alloy fabricated by technology of traditional powder metallurgy.