Ultrasonic-assisted preparation of complex-shaped ceramic cutting tools by microwave sintering

Abstract Complex-shaped ceramic tools were prepared by ultrasonic-assisted molding technology and microwave sintering. A uniaxial ultrasonic vibration compaction system was designed. The effects of ultrasonic vibration and molding pressures on mechanical properties and microstructures of A2O3 and Al2O3/SiC complex-shaped milling cutters were investigated by simulations and experiments. The results indicated that the density was distributed unevenly within the green ceramic tool samples, especially poor in the tool edges. These drawbacks were well improved by ultrasonic-assisted molding technology and microwave sintering. Applying ultrasonic vibration during the compaction process of green ceramic tool samples could improve the densification, hardness and reduce the randomness of mechanical properties of the sintered ceramic tool materials, especially for the difficult-to-sinter composite ceramics (with poor density). For A2O3 ceramic tool, fully dense microstructure was achieved, and for Al2O3/SiC ceramic tool, the cutting edges showed better density than that of the interior body, which was beneficial to improve the abrasion resistance of cutting tool.