Investigation of the Effect of Tungsten Carbide (WC) Nanopowder on Iron-Based Powder Structural Materials

Abstract

Studies of a powder used as a modifier obtained from solid-alloy waste, such as tungsten carbide (drill balls), are presented. Dispersion, particle morphology and phase analysis of the powder were studied. The powder obtained from solid-alloy waste is a phase – it is tungsten carbide WC, it consists of nanoobjects of various shapes (nanoparticles, nanoplastics) up to 100 nm in size, with a slight presence of agglomerates up to 250 nm in size. The influence of tungsten carbide nanopowder as a modifier on the mechanical properties (strength and hardness) of PK70D3 iron-based powder structural steel has been studied. For the study, two different modes of preparation of powder alloy have been used with the use of one-stage and two-stage sintering. The influence of additive nanopowder of tungsten carbide on the mechanical properties of structural alloy powder based on iron PK70D3 has been defined: strength increases by more than 23% (in single-stage sintering), by more than 28% (in double-sintering), hardness decreases by more than 6% in single-stage sintering and increases by more than 26% with two stages of sintering, compared to the initial alloy. It has been shown that samples, obtained using double sintering with a tungsten nanopowder modifier (2.5%), have higher values of strength (more than 80%) and hardness (more than 13%), compared to modified samples, obtained by single-stage sintering technology. Thus, the modification of a 2.5 % nanoprobe of tungsten carbide, a widely used structural powder alloy based on iron PC70D3 allows for a significant change in mechanical properties. The use of powder alloys in double sintering technology provides the material hardness and the strength increase.