Mechanical and electrophysical properties of a composite obtained by high thermobaric treatment of W-Cu-Co-C material

Abstract

This study proposes a new method for the synthesis of cemented carbides in the tungsten carbide-cobalt
(WC-Co) system under high pressure and high temperature (HPT) conditions. The aim of the research is
to eliminate the problem of the balance of the relationship between hardness and strength in this twocomponent
system. WC-Co composites were obtained by direct synthesis from elemental tungsten,
carbon, and cobalt under thermobaric conditions, i.e., in the temperature range of 4~8 GPa and
1200~2200 °C, which allowed the formation of the WC phase and compaction to occur in one stage.
After such analyses as structural XRD, SEM, and TEM, the results of the mechanical testing phase are
reflected in the article. Mechanical tests were performed for such parameters as hardness, viscous
fracture, abrasion resistance, and electrophysical properties - electrical resistance and magnetic
saturation. WC-Co composites obtained at high pressure and temperature achieve hardness of 13~15 GPa
and viscous fracture resistance of 12~14 MPa·m1⁄2, exceeding the values characteristic of the WC-6Co
class widely used in production, i.e., such indicators as hardness of 12~14 GPa and viscosity of 8~11
MPa·m1⁄2. The results show that the synthesis of WC-Co can be proposed as an effective alternative to
the traditional sintering technology, demonstrating the achievement of high density of the composite
material, creating high mechanical properties and heat resistance of WC-Co materials of the same
composition.