This group contains grades that have had the distribution of their binder phase modified in such a way as to create a material with properties different in the surface zone compared with the bulk.
This entirely new concept, developed by Hyperion Materials & Technologies, enables components to be produced that contain distinct microstructural zones, each with different binder content. Thus, each zone has different properties – hence the term “Dual Property”.
Hyperion DP carbide
For conventional cemented carbides, wear resistance and toughness are related in such a manner that an improvement in one property results in a deterioration in the other.
Hyperion has developed an entirely new type of WC-Co cemented carbide in which wear resistance and toughness can be improved independently of each other. By means of a controlled redistribution of the cobalt binder phase, cemented carbide components can now be made that contain three distinct microstructural zones, each of which has different properties. These gradients, together with the differences in thermal expansion, redistribute the internal stresses. For example, it is possible to create a very hard and wear-resistant surface layer that is simultaneously pre-loaded with compressive stresses to prevent the initiation and propagation of cracks.
Cemented carbide having such a distribution of properties has high wear resistance at the surface combined with a tough core. These materials have therefore been given the designation DP – Dual Property. Carbide component’s initial application area was in rock drilling. Other applications of carbide components, such as tools for tube and wire drawing and cold heading dies, have also confirmed improved performance.