USING INTENSE PLASTIC STRAINING FOR HIGH-STRAIN RATE SUPERPLASTICITY

Ultrafine grain sizes may be introduced into bulk samples by using the intense plastic straining technique equal-channel angular pressing. T his article describes the principles of equal-channel angular pressing and demonstrates the application of this procedure to attain ultrafin e grain sizes in an Al-3Mg solid-solution alloy and a commercial east Al-Mg-Li-Zu alloy. Provided there is stability of these ultrafine grai ns at elevated temperatures, as in the Al-Mg-Li-Zr alloy, equal-channe l angular pressing may be used as a processing tool to achieve high-st rain-rate superplasticity in materials that are not potentially superp lastic. These results have important implications for reducing the lon g production times that are associated with the fabrication of complex parts using super-plastic forming.