An airfoil having a melting temperature of at least about 1500° C. and comprising a first piece and a second piece joined by a braze to the first piece. The first piece comprises one of a first niobium-based refractory metal intermetallic composite and a first-based refractory metal intermetallic composite, and the second piece comprises one of a second niobium-based refractory metal intermetallic composite and a second molybdenum-based refractory metal intermetallic composite. The braze joining the first piece to the second piece is a semi-solid braze that comprises a first component and a second component. The first component of the semi-solid braze comprises a first element and a second metallic element, wherein the first element is one of titanium, palladium, zirconium, niobium, germanium, silicon, and hafnium, and the second metallic element is a metal selected from the group consisting of titanium, palladium, zirconium, niobium, hafnium, aluminum, chromium, vanadium, platinum, gold, iron, nickel, and cobalt, the second metallic element being different from the first element. The second component has a melting temperature of at least about 1450° C. and comprises one of niobium, molybdenum, titanium, hafnium, silicon, boron, aluminum, tantalum, germanium, vanadium, tungsten, zirconium, and chromium. This abstract is submitted in compliance with 37 C.F.R. 1.72(b) with the understanding that it will not be used to interpret or limit the scope of or meaning of the claims.