Post-processing heat treatments of Ti-6Al-4V parts produced by additive manufacturing are essential for restoring the peculiar martensitic structure that originates from the extremely high cooling rates typical of this technology. In this study, the influence of a 1050 °C annealing on a Ti-6Al-4V alloy, produced by additive manufacturing, on the minimum creep rate dependence on applied stress and temperature, was investigated at 650 °C. Experimental data obtained after two different subcritical annealings were also considered for comparison purposes. The analysis of the experimental creep data demonstrated that the alloy annealed at the highest temperature exhibited lower creep rates. The improved creep response was attributed to the combined effect of the presence of extended α-β interfaces and of a small volume fraction of Ti3Al particles.
In this work a W coating was deposited through PS in Ar-H2 atmosphere on a substrate of CuCrZr with an interlayer consisting of gradually changing fractions of Cu and W. The W coating and the interlayer showed good adhesion and no cracks were observed. The hardness of W and Cu along the interlayer was determined by nano-indentation tests and the results showed that a hardness gradient does exist in both the metals. Microstructural examinations suggest that the hardness gradient depends on the texture, which exhibits significant differences along the interlayer: multiplication and movement of dislocations, and localized plasticity under the indenting tip are strongly affected by grain orientation.