Journal Archive

Not long ago structural intermetallics were metallurgical curiosities rather than the focus of a serious campaign to topple the supremacy of nickel-based superalloys. Indeed, a handful of intermetallic compounds, notably the titanium and nickel aluminides, have succeeded in making it to the point of operational testing; but, if anything, they have highlighted the challenges facing a new generation of ultra-high temperature materials. Two constraints in particular have directed developments. First, at the core of the development of intermetallics, is the need to address the dual requirements of low-temperature toughness and high-temperature strength central to structural applications. Second, the operating conditions of interest (temperatures above 1150°C) call for a marked improvement in the environmental resistance of the materials. In these respects, systems based on platinum group metals deserve attention. The potential benefits resulting from using composite microstructures based on platinum, iridium and ruthenium are highlighted here, using collaborative studies being undertaken by Mintek and a number of alloy development centres.