Cemented carbide body with improved high temperature and thermomechanical properties

US6423112B1 · kind B1 · utility

Assignee

• SANDVIK AB · SE

Inventors

• Jan Akerman · Stuvsta-Snättringe, SE
• Thomas Ericson · Stuvsta-Snättringe, SE

Key dates

• Filing date: Apr 10, 2000
• Grant date: Jul 23, 2002
• Expiry date: Apr 10, 2020

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E21B10/56
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

There is now provided a cemented carbide grade for rock excavation purposes with 88-96 weight % WC, preferably 91-95% weight % WC, with a binder phase consisting of only cobalt or cobalt and nickel, with a maximum of 25% of the binder being Ni, possibly with small additions of rare earth metals, such as Ce and Y, up to a maximum of 2% of the total cemented carbide. The WC grains are rounded because of the process of coating the WC with cobalt, and not recrystallized or showing grain growth or very sharp cornered grains like conventionally milled WC, thus giving the bodies surprisingly high thermal conductivity. The average grain size should be from 8-30 &mgr;m, preferably from 12-20 &mgr;m. The maximum grain size does not exceed 2 times the average value and no more than 2% of the grains found in the structure are less than half of the average grain size.