WC-based composites made from WC/Ti powder mixtures using HEBM-SPS as alternative for WC-Co cemented carbides
GARBIEC D. 1, WI?NIEWSKI J. 1, KRZY?ANIAK W. 1, ADAMEK G. 2
1 ?ukasiewicz Research Network – Pozna? Institute of Technology, Poznan, Poland; 2 Poznan University of Technology, Institute of Materials Science and Engineering, Poznan, Poland
Co-free cemented carbides are currently one of the most investigated tool materials for application in cutting inserts. Lots of attempts have been made in replacing cobalt, however, some metals like titanium were not been deeply investigated. Titanium, which has a similar melting point to cobalt, is far less expensive and may be one of the most promising solutions. In this work, we aim to obtain a new type of tool material from WC/Ti high-energy ball milled powders which then were spark plasma sintered. Even if several authors have already reported some research on WC-Ti composites, they did not obtain satisfactory results. Our novelty is the sintering of WC/Ti powder mixtures with 5 and 25 wt% of titanium using typical and fast SPS regimes. For this reason, to avoid a thermal gradient on the cross-section of the densified samples, the tool setup was fully thermal insulated by graphite felt. The microstructures, grain size, and phase compositions of the manufactured ceramic matrix composites were investigated by SEM-EDS, EBSD, and XRD. It was noticed that titanium fully reacted with tungsten carbides and WC-TiC composites were manufactured. The Vickers hardness of these composites is higher than 2000 HV10, and indentation fracture toughness is higher than 8 MPa·m1/2, when the initial titanium content is 5 wt%. No notable carbon uptake from the graphite tool was detected. Using the combined manufacturing route of high-energy ball milling and spark plasma sintering, it is possible to obtain WC-based composites from WC/Ti powder mixtures with promising mechanical properties and high application potential.