Co-free drill bit

Purpose and goal:

Sweden is a strong material-producing country, and world leading when it comes to producing fossil-free steel and cemented carbides. This project aims to combine these two materials in a composite to solve sustainability issues with existing rock drilling tool.

Traditionally, rock drilling tools consist of tungsten carbide in a binder phase of cobalt. In the new material, the binder phase has been replaced by a steel with a martensitic/ferritic matrix with a certain amount of retained austenite, which under an applied stress is transformed to martensite through a TRIP effect.

Expected results and effects:

A new binder phase could improve the mechanical properties of cemented carbide-based tools for rock drilling as well as solve several problems from a sustainability point of view connected to cobalt. Cobalt is both carcinogenic and to a large extent mined in conflict areas. In addition, the project´s results could pave the way for a new group of composite materials for many different applications.

Approach and implementation:

The project is divided into four workpackages, WP. In WP 1 calculations and simulations to find a recipe for the new binder phase composition will be performed at KTH using materials design and ICME, Integrated Computational Materials Engineering. In WP 2 drill bits based on the recipe suggested in WP 1 is manufactured following a powder metallurgical process by Sandvik Mining.

In WP 3 the sintered drill bits from WP 2 are characterized by Sandvik Mining together with KTH. In WP 4 field tests will be performed at one of Boliden’s mines by Boliden Mineral and Sandvik Mining.