Microstructure and properties of binderless μWC obtained using the electroconsolidation method

Abstract

This paper contributes to the knowledge of binderless tungsten carbide (WC), which attracts the attention of many engineers and scientists for its superior properties, but its application is limited due to difficulties with the consolidation of initial powders. In the present study, the microstructure and mechanical properties of binderless WC, sintered with the electroconsolidation technique from the initial powder of a grain size of 100–200 nm, were investigated. The material was compared with nWC sintered with the same method from a nanopowder with particles of size ca. 70 nm. The binderless μWC demonstrated hardness of HV = 30.06 ± 0.09 GPa, which is almost 14% higher than that of nWC, but its fracture toughness was lower (KIC = 6.59 ± 0.46 MPa·m1/2 under 1 kg load). These differences can be attributed to the improved homogeneity of the μWC microstructure, where no large agglomerates appeared to be present in nWC. The measured plastic properties, with no signs of brittle fracture, further confirm the applicability of the binderless WC under contact stress conditions.