Ultrafine-grained WC-based ceramics prepared via two-step oscillatory pressure sintering

摘要

Grain growth in ceramic-based composites during sintering has always been an unavoidable problem. Based on the theory of fine-grained reinforcement, the concept of rapid densification was coupled with the inhibition of grain growth to fabricate ultrafine-grained WC-based ceramics. Herein, by combining two-step sintering with oscillatory pressure sintering (OPS), a new sintering process-two-step oscillatory pressure sintering (TSOPS), was used for the preparation of ultrafine-grained WC-based ceramics. The comparison of the OPS with the TSOPS validated the feasibility of the strategy in achieving homogeneous and fine-grained microstructures. The optimum mechanical properties of Vickers hardness, fracture toughness, and flexural strength reached up to 29.56 GPa, 7.97 MPa m1/2 and 1591 MPa, respectively. A developed TSOPS process was proposed and proved to dominate the grain size distribution homogenizing, which contributed to the simultaneous enhancement of mechanical properties of the ceramics.

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