Keyword: «microhardness»

The article presents the results of studies of the mechanical properties of prototypes of hard-alloy drilling inserts with ultrafine additives of magnesium spinel. In the composition of the prototypes, the percentages of ultrafine additives of magnesium spinel varied from 0.1% to 1.0%. The formation of a homogeneous structure in the volume was revealed. The absence of conglomerates of ultrafine additive powders on the surface was revealed. The work aims to analyze the mechanical properties of prototype drill inserts made of tungsten-cobalt alloys, which differ in the content of an ultrafine additive. In work, the instruments of the Central Collective Use Center of the Federal Research Center of the Yankee Scientific Center of the Siberian Branch of the Russian Academy of Sciences and CJSC "DV – Technology" were used. It has been shown that adding ultrafine powder of magnesium spinel to the charge composition of the tungsten-cobalt matrix increases density and hardness.

In this paper, the processes of structure formation during gas-thermal electric arc metallization with powder wire are considered. The basic composition of the charge is nickel alloy PGSR-4. Niobium powders were selected as modifying additives, the content of which in the charge of powder wires is: 0.1%, 0.3%, 1% and 5% by weight. The influence of niobium content on carbide formation, on the ratio of structural components, on the formation of oxide phases, and the dispersion of the surfacing microstructure are shown. Tribological studies have shown that the wear of samples decreases by an order of magnitude, starting with the addition of 0.3% niobium. With a niobium content of 1% and 5% in the powder wire, the wear resistance remains high, but the mass losses of the samples and the counterbody are balanced, which is due to the grinding of the microstructure and an increase in the uniformity of micromechanical properties.