Precipitation behavior and tensile properties of stress-aged Ti-2.5Cu alloy

Solution treated Ti-2.5Cu alloy was aged under a compressive stress of ~200 MPa. TEM investigations show that three variants of precipitated Ti₂Cu plates are observed in conventionally aged samples without compressive stress. However, in the stress-aged samples, for most grains, one or two variants of Ti₂Cu plates could be observed, which indicate the variant selection effect of precipitated Ti₂Cu plates resulting from external compressive elastic stress. Lower yield strength and higher elongation is observed during subsequent tensile tests due to the variant selection effect.