Abstract: To provide a nickel based brazing filler metal which does not contain at all boron (B) or phosphorus (P) that is likely to form a hard and brittle compound in the brazed layer, in which the liquidus is lowered below 1,100° C. by adding a small amount of silicon (Si) and is abundant in ductility, heat-resistance and corrosion resistance. This is attained by a nickel based brazing filler metal characterized by containing manganese (Mn) of 13 to 20% by wt. and silicon (Si) of 5 to 7% by wt. added as melting point depression elements and chrome (Cr) of 16 to 21% by wt. and the balance consisting of nickel (Ni) and the impurities.

Abstract: A method of diffusion bonding of aluminum or an alumina ceramic to aluminum, an alumina ceramic or a metal other than aluminum, which comprises interposing an aluminum alloy prepared by including 0.2 to 3% by weight of magnesium and/or 0.1 to 1.5% by weight of lithium into aluminum or an aluminum alloy between the surfaces of materials to be bonded, and heating said surfaces to be bonded of these materials under pressure at a temperature at which magnesium or lithium diffuses.