OPTIMISATION OF STRAIN RATE SENSITIVITY DURING SUPERPLASTIC DEFORMATION OF Al-Li-ALLOY LITAL A N. RIDLEY, D.W. LIVESEY and J. PILLING J. Phys. Colloques, 48 C3 (1987) C3-251-C3-256 DOI: 10.1051/jphyscol:1987328