Sintering, thermal stability and mechanical properties of ZrO2-WC composites obtained by pulsed electric current sintering

Abstract

ZrO 2 -WC composites exhibit comparable mechanical properties as traditional WC-Co materials, which provides an opportunity to partially replace WC-Co for some applications. In this study, 2 mol.% Y 2 O 3 stabilized ZrO 2 composites with 40 vol.% WC were consolidated in the 1150°C-1850°C range under a pressure of 60 MPa by pulsed electric current sintering (PECS). The densification behavior, microstructure and phase constitution of the composites were investigated to clarify the role of the sintering temperature on the grain growth, mechanical properties and thermal stability of ZrO 2 and WC components. Analysis results indicated that the composites sintered at 1350°C and 1450°C exhibited the highest tetragonal ZrO 2 phase transformability, maximum toughness, and hardness and an optimal flexural strength. Chemical reaction of ZrO 2 and C, originating from the graphite die, was detected in the composite PECS for 20 min at 1850°C in vacuum.

Self-Lubricating Effect of WC/Y–TZP–Al2O3 Hybrid Ceramic–Matrix Composites with Dispersed Hadfield Steel Particles during High-Speed Sliding against an HSS Disk

“…It was reported earlier [45,46] that the WC grains may form agglomerates when sintering the WC-ZrO 2 and WC-Al 2 O 3 composites even if the source powder blend was thoroughly homogenized. In our case, there is another factor facilitating the agglomeration because sinter-forging was carried out at 1350 • C, i.e., above the 1143 • C that is the WC-Fe eutectic point [37].…”

ED-machinable Ceramics with Oxide Matrix: Influence of Particle Size and Volume Fraction of the Electrical Conductive Phase on the Mechanical and Electrical Properties and the EDM Characteristics

“…In such cases, electrical discharge machining (EDM) of ceramics is a promising approach to reduce the manufacturing cost. Composites with a strong and tough TZP matrix and a percolating electrically conductive carbide dispersion (such as tungsten carbide, WC), are known ED-machinable materials [4,5]. A sufficiently high electrical conductivity is widely accepted to be the prerequisite for electrical discharge machining [6].…”

Corrosion Behavior of ZrO₂-Mo Composite in Na₂SO₄ Solution

“…However, the relative poor shock resistance limited its applications. Thus, ZrO 2 -besed composites had been developed, and these composites exhibit good properties [3,4,5].…”