Stacking Faults in a Cu‐15 at% Al Alloy. I. The Short Range Order and Temperature Dependence of the Stacking Fault Energy

An experimental study was made of the short range order (SRO) and temperature dependence of the stacking fault energy (SFE) for a Cu‐15 at% Al alloy using (110) single crystal foils. The SFE was determined using measurements form threefold nodes, intrinsicextrinsic fault pairs, and Frank triangles. Good quantitative agreement was obtained for the SFE determined form these three defects. A SRO dependence of the SFE was found by measuring the SFE form foils quenched from different annealing temperatures which are known to vary the degree of SRO [4]. A reversible temperature dependence of the SFE was found where the SFE increased with increasing temperature for both intrinsic and extrinsic faulting. The ratio of extrinsic to intrinsic fault energy was found to be 1.14 ± 0.08.