Relationships among thermomechanical treatments, microstructure, and tensile properties of a near beta-titanium alloy: β-CEZ: Part II. Relationships between thermomechanical treatments and tensile properties

The tensile properties of the β-CEZ titanium alloy (Ti Al, 2Sn, 4Zr, 4Mo, 2Cr, 1Fe wt. %) have been investigated at intermediate temperatures as a function of the thermomechanical treatments. the strength and ductility have been correlated with the microstructural changes caused by the various heat treatments. It is found that the highest yield strength is associated with a structure containing a small area fraction, a small size, and a high density of primary α platelets (α_p). Moreover, the size of the secondary α phase (α_s) has been found to affect the yield strength. It is concluded that the ductility is enhanced by a high area fraction of α_p platelets and is also sensitive to the density and the morphological orientation of the α_p platelets. The interfaces between the α_p and β phases play a dominant role in β-CEZ tensile behavior, and transgranular fracture is the main failure feature of this alloy.