The orientation relationship of α-Co precipitates in melt-spun Cu70Co30

A TEM investigation on the orientation relationship of α-Co precipitates in a copper matrix has revealed that these f.c.c precipitates, approximately 15–20 nm in diameter, were formed in Cu70Co30 ribbons during melt-spinning. After annealing at 573 K, these precipitates grew to about 30–50 nm in diameter. Analysis of selected area diffraction patterns (SAPD) combined with the dark field imaging technique confirms that the orientation relationship between these α-Co precipitates and the Cu matrix is not a cube-cube relationship, but a twin-type one, i.e, “111”Co//“111”Cu and 〈110〉Co//〈110〉Cu.