Papers by Keyword: Sheet Rolling

Abstract: The influences of rare earth elements addition on the crystallographic texture and microstructural evolutions are examined during rolling and annealing of Mg-sheets. In case of Nd or Y additions, dynamic recrystallisation is suppressed such that the deformed microstructure is observed after hot rolling with relatively large strain per pass. Cold rolled binary Mg-Nd alloy sheet shows strong texture with splitting of the basal poles in the rolling direction, however, the texture intensity decreases significantly during the recrystallisation annealing. From the comparison of deep drawing behaviours between commercial ZE10 and AZ31 sheets, it is observed that the addition of the rare earth elements and accompanying texture changes result in the improved formability.

Abstract: Mechanical properties of a Ti2AlNb-based intermetallic alloy both at room and elevated temperatures were considerably improved due to formation of a homogeneous microstructure with the average grain size of about 300 nm. At room temperature, elongations up to 25% were obtained and the ultimate strength reached 1400 MPa. The alloy exhibited superplastic behavior in the temperature range of 850-1000°C. The maximum elongation of 930% and steady state flow stress 50 of about 125 MPa were obtained at 900°C and strain rate of 4.210-3 s-1. The nanostructured material was used for production of intermetallic sheets and multilayer composite plates consisting of alternating layers of orthorhombic intermetallic and commercial high temperature titanium alloy. Ti2AlNb-based sheets and composites exhibited improved mechanical properties.

Abstract: Homogeneous nanocrystalline structure with the average grain size of about 300 nm was produced in Ti2AlNb-based intermetallic alloy by a thermomechanical processing which included multistep isothermal forging at temperatures below the β-transus and intermediate annealings. Nanostructured material possessed excellent mechanical properties. At room temperature, elongations up to 25% were obtained and the ultimate strength reached 1400 MPa. The alloy exhibited superplastic behavior in the temperature range of 850-1000°C. The maximum elongation of 930% and steady state flow stress σ50 of about 125 MPa were obtained at 900°C and strain rate of 4.2×10-3 s-1. The rolling temperatures of nanostructured alloy were defined from analysis of its mechanical behavior at a typical rolling strain rate of about 10-1 s-1 and intermetallic sheets with improved mechanical properties were produced.