James A. Forster

THE PROCESSING AND EVALUATION OF CLAD METALS

Clad metals are a specific form of composites in which the materials are arranged in a layered structure. Cold-roll bonding techniques are employed to produce more than 20,000 tonnes of clad metal laminates each year in the United States. This article is an introductory description of the processing steps in cold-roll bonding, the nature of the bond created in this process, and the methods used to evaluate the bond’s strength.

Producing titanium aluminide foil from plasma-sprayed preforms

High-strength titanium alloy and titanium aluminide foils are required for fabricating composite structures and honeycombs for advanced aircraft engines and airframes. Titanium aluminide alloys possess limited workability, which results in significant yield loss when these materials are produced by the conventional ingot metallurgy route. This article describes the use of induction plasma spray technology to fabricate foil preforms of a titanium alloy and a titanium aluminide. These plasma-sprayed preforms were converted into 100% dense wrought titanium aluminide foil by a roll-consolidation process. The microstructure and mechanical properties of titanium aluminide foil produced from plasma-sprayed preforms were virtually identical to those of conventional ingot metallurgy foil. The plasma-spray plus roll-consolidation route may lead to the production of titanium aluminide foil as continuous coil, which would improve process efficiency and yield high-quality titanium aluminide foil at low cost.