APPLICATION OF ULTRASOUND ON JOINING OF CERAMICS TO METALS

Ultrasonic brazing was applied to join ceramics of alumina and silicon carbide to metals using Zn, Zn-5Al and Zn100-x(Al0.6 + Cu0.4)x (x = 0-30) filler metals. The intensity of ultrasound was 1 kW and 18 kHz. The strength of joint was measured by fracture shear loading of 1.67 x 10(-2) mm/s. The ceramics were metallized by applying ultrasound in filler metals, and then the metallized ceramics were brazed to metals with the same filler metals. The strength of the Al2O3/Cu joint with Zn-6Al-4Cu filler was improved by increasing the application time of ultrasound or increasing the metallizing temperature. The strength of the Al2O3/Cu joint exhibits a maximum with the Zn100-x(Al0.6 + Cu0.4)x filler at x = 0.2. SiC was also brazed to metals by applying ultrasound using Zn-5Al, where the metals were Ti, Fe, Cu and SUS304. The application of ultrasound during brazing accelerates the wetting of molten metals against ceramics and improves the strength of the ceramic/metal joint.