Microstructure and mechanical behavior of Ti-Cu alloys produced by semisolid processing

The mechanical properties of Ti-Cu alloys processed via thixoforming were evaluated. Ti-Cu (25, 27, and 29 wt.% Cu) ingots were produced via arc melting, homogenization at 950 degrees C for 24 h, and hot-forging at 900 degrees C, followed by thixoforming at a speed of 8 mm/s after isothermal heat treatment at 1035 degrees C for 300 s. The thixoformed alloys exhibited good mechanical strength, limited plasticity under tensile loading, and reasonable plasticity under compressive loading. The mechanical strength and plasticity decreased as the Cu content increased as a result of the increasing volume fraction of the peritectic Ti2Cu phase (transformed liquid), which exhibited a lower strength and plasticity than the alpha + Ti2Cu regions (transformed solid). These findings indicated that the trade-off between the mechanical properties and semisolid processability is largely governed by the Cu content.