Abstract: A ultrasonic tool horn for use in ultrasonic machining, welding, etc. has a horn main body made of a heat-treatable aluminum alloy. The aluminum alloy is heat treated so as to be as hard as 100 or more on the Vickers hardness scale. In one embodiment, a thin intermediate layer of a non-heat-treatable aluminum alloy is provided between the horn main body and a ceramic tool attached to a slender end portion of the horn main body.

Abstract: A nickel plate is brazed to a shaft of a ceramic turbine wheel by way of a brazed joint layer of the composition consisting of 20 to 70 wt % of silver, 1 to 20 wt % of palladium, 10 to 60 wt % of nickel and 1 to 10 wt % of titanium. The nickel plate is brazed to a metal shaft by interposing therebetween a tungsten base alloy plate and another nickel plate. The nickel plates, tungsten base alloy plate and metal shaft are brazed together by way of respective brazed joint layers of the composition which does not include titanium. A metal sleeve is installed on the shaft of the ceramic turbine wheel, metal shaft and the metal plates. The metal sleeve is brazed to the metal shaft by way of a brazed joint layer of the composition including less than 1 wt % of titanium. The brazed joint layer for brazing the metal sleeve and metal shaft together is formed by the filler metals for forming the brazed joint layers for brazing the nickel plates, tungsten alloy plate and metal shaft together.

Abstract: Joined ceramic and metal is characterized by ceramic and metal thermally joined through an intermediate layer. The intermediate layer is composed of 20-70% by weight of silver, 1-20% by weight of palladium, 10-60% by weight of nickel and 1-10% by weight of titanium. The joined ceramic and metal has sufficient joining strength both at normal temperature and at high temperature, because the joined ceramic and metal suffers little deterioration even at high temperature. Since the joined ceramic and metal has the characteristics of ceramic such as resistance to heat, corrosion and wear, it can be used for a structure operated at high temperature such as a gas turbine engine, a turbo charger rotor, a piston, a suction valve, and an exhaust valve.