Effect of concurrent precipitation on recrystallization textures in commercial Al-Mn alloys

The effect of concurrent precipitation on recrystallization textures in AA 3003 aluminum alloys was investigated using X-ray diffraction and electron backscattering diffraction（EBSD） analyses. A weak recrystallization texture was observed in the AA 3003 alloy annealed at 783 K due to the high annealing temperature. Under the same conditions, extremely high P {011 } （ 111 ） recrystallization textures were detected in the AA 3003 alloy added with 0. 39% Sc. Based on the EBSD results, no intensely preferential orientation nucleation of recrystallization grains was observed in the early stage of recrystallizafion for both alloys. However, concurrent precipitation strongly retarded the growth of recrystallization grains, except for P nucleation sites, thereby conferring an apparent initial growth advantage for P nucleation sites compared with other nucleation sites. Therefore, a sharp P {011 } 〈 111 〉 texture appeared in concurrently precipitated AA 3003 alloys.

Hot Deformation Behavior and Dynamic Recrystallization Characteristics in a Low-Alloy High-Strength Ni–Cr–Mo–V Steel

This study presented a quantitative investigation of deformation behavior and dynamic recrystallization of low-alloy high- strength Ni-Cr-Mo-V steels during hot deformation. A series of isothermal compression experiments were performed at temperatures ranging from 800 to 1200 ℃ and strain rates from 0.01 to 10 s^-1 with a height reduction of 60%. A complete Arrhenius constitutive model and processing maps were developed. The results showed that the constitutive model had the ability to predict the flow stress with an average absolute relative error of 〈 5.7%. The processing maps constructed at strains of 0.2, 0.4, and 0.8 showed that flow instability was prone to occur at higher strain. Dynamic recrystallization tended to take place at higher temperatures （900-1200 ℃） and lower strain rates （0.01^-1 s^-1）. The critical strain for the onset of dynamic recrystallization was determined, and a kinetics model was developed. The predicted results for recrystaUization volume fraction and flow stress were compared with the experimental data, which indicated that the model was accurate and reliable.

Reveal the growth mechanism in perovskite films via weakly coordinating solvent annealing

In this study, we investigated the nucleation mechanism of perovskite films by employing isopropanol(IPA), a weakly coordinating solvent, to anneal both PbI2 and CH3 NH3 PbI3 in the sequential deposition and CsPbI3 in the one-step deposition. IPA solvent annealing(IPA SA) of PbI2 films was carried out at different temperatures. The grain size,compactness, roughness and morphology of PbI2 and CH3 NH3 PbI3 films were seriously affected by annealing methods. Similarly, weakly coordinating solvent annealing process was also employed to anneal all inorganic CsPbI3 perovskite in a one-step method. A continuous and dense CsPbI3 film with uniform grain size was obtained. We recognized that weakly coordinating solvent annealing for perovskite could regulate the dissolution-recrystallization process via controlling the volume of residual solvent in perovskite intermediate films. The power conversion efficiency(PCE) of conventional CH3 NH3 PbI3 perovskite solar cells(PSCs)reached 17.4% and that of CsPbI3 PSCs reached 2.5% based on this sequential IPA SA process.