Influence of Deformation Temperature on the Formation of Contacts in Titanium Powder Ribbons Produced by Symmetric and Asymmetric Rolling

The influence of various rolling methods on the mechanical properties of titanium ribbons was studied. Ribbons produced by asymmetric rolling showed 100% density and higher strength compared to ribbons produced through symmetric rolling. The temperature sensitivity of contact formation and mechanical behavior of ribbons rolled asymmetrically was determined by thermal variations in the plastic deformation mechanisms specific to titanium. In this regard, three temperature ranges were identified: low, intermediate, and high. In the low-temperature range (<100 °C), the elastic modulus and proportionality limit were significantly higher than those from symmetric rolling, although still inferior to the properties of the compact material. In the intermediate-temperature range (100–300°C), the elastic modulus and proportionality limit in the rolling direction matched those of compact titanium but were approximately three times greater than those found for samples tested transversely. In the high-temperature range (>300°C), the elastic modulus in both longitudinal and transverse directions was comparable to that of the compact material, while the proportionality limit surpassed the compact material significantly, owing to the deformation substructure observed in the ribbons. Asymmetric rolling significantly enhanced the mechanical properties of titanium ribbons compared to symmetric rolling. This enhancement was due to the shear strain component that facilitated contact formation at particle boundaries. Under optimal deformation conditions, the ribbons achieved a strength limit of ~800 MPa, comparable to the strength of ribbons produced conventionally. The plasticity of the ribbons did not exceed 1.5% because of their propensity for interparticle fracture.