Instability map for hot working of 6061 Al-10 vol% Al2O3 metal matrix composite

A simple condition for metallurgical instability, useful in the development of processing maps for analysing high-temperature forming of metals, is suggested following a criterion based on continuum principles as applied to targe plastic flow proposed by Ziegler. it can be used for any type of flow stress versus strain rate curve. This criterion has been validated using the flow stress data of a 6061 Al-10 vol% Al2O3 metal matrix composite with microstructural observations. Optimum hot working conditions based on the instability map are suggested for this material.