Article
Materials Science, Multidisciplinary
Masoud Mirzaee, Ali Reza Khodabandeh, Gholamreza Ebrahimi
Summary: The study revealed that Nimonic 80A alloy exhibits different dynamic recrystallization characteristics at different temperatures and strain rates, with precipitation having an influence on the recrystallization process.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2022)
Article
Materials Science, Coatings & Films
Ali Gunen, Kadir Mert Doleker, Mehmet Erdi Korkmaz, Mustafa Sabri Gok, Azmi Erdogan
Summary: The nickel-based superalloy Nimonic 80A was borided using silicon-free boriding powders at temperatures of 850°C and 950°C for 2-4 hours, resulting in a smooth boride layer mainly composed of Ni2B with minor amounts of CrB, Cr2B, and Cr5B3. The hardness and elastic modulus of the boride layer increased with chromium content, while fracture toughness decreased. Boriding treatments improved dry sliding wear resistance, with higher values achieved with increased time and temperature, although they had no significant effect on oxidation resistance.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Chemistry, Physical
Ke Tang, Zhibo Zhang, Jin Tian, Yake Wu, Feng Jiang
Summary: The study on hot deformation behaviors of supersaturated Inconel 783 superalloys revealed the optimal temperature and strain rate range to be 1100-1200 degrees C and near or below 0.1 s(-1) but higher than 0.01 s(-1). The microstructural observation showed that the recrystallized degree and grain size were affected by temperature and strain rate differently.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Jin Yang, Jiao Luo, Xiangyang Li, Miaoquan Li
Summary: This study investigates the correlation between microstructure and deformation-solution parameters of GH4586 superalloy through isothermal compression, solution treatment, EBSD, and TEM observations. It clearly illustrates the mechanisms of recrystallization, twin evolution, gamma' precipitation, and their interaction. The results show that the processes of dynamic and static recrystallization are controlled by different mechanisms, and the evolution of twin boundaries during deformation is influenced by losing twin's identity and nucleation of new twins. Fine gamma' precipitates hinder recrystallization but also have a noticeable influence on the formation of new twins.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Metallurgy & Metallurgical Engineering
Li Fulin, Fu Rui, Bai Yunrui, Meng Lingchao, Tan Haibing, Zhong Yan, Tian Wei, Du Jinhui, Tian Zhiling
Summary: GH4096 alloy is used in advanced gas turbine engines due to its excellent properties. In this study, GH4096 was processed through an advanced cast and wrought route to avoid expensive power metallurgy (P/M) route. The effects of initial grain size and strengthening phase on hot deformation behavior and dynamic recrystallization were studied.
ACTA METALLURGICA SINICA
(2023)
Article
Materials Science, Multidisciplinary
Zhiguo Wang, Fei Gao, Shuai Tang, Chengang Li, Zhenyu Liu
Summary: A series of solution annealing experiments and quasi in-situ observation were conducted to investigate the grain growth behaviors in hot rolled 316H austenitic stainless steel with heterogeneous microstructure. It was found that during high temperature direct heating, grains grew unevenly with size differences, while stepping heating resulted in uniform grain growth and distribution, providing a new idea for regulating grain size in manufacturing heavy austenitic stainless steels.
Article
Materials Science, Multidisciplinary
Jianming Li, Yuting Wu, Hongjun Zhang, Xingzhong Zhang
Summary: During hot deformation of nickel-based superalloys, dislocations undergo various processes such as production, annihilation, and rearrangement into substructures, which have a significant impact on the dynamic recrystallization process. Understanding the relationship between dislocation substructures and recrystallization mechanisms is crucial. Through isothermal compression experiments, the evolution of dislocation substructures and associated recrystallization behaviors were studied in a coarse-grained Co-free nickel-based superalloy. The results showed that dislocation substructures governed the dynamic recrystallization mechanisms and acted as precursors for new grains, while dynamic recovery promoted the transition of dislocation substructures. Continuous dynamic recrystallization was influenced by independent substructures within deformed grains, while discontinuous dynamic recrystallization was influenced by substructures attached to original grain boundaries. The sacrifice of dislocation substructures drove recrystallization kinetics, as the recrystallized volume fraction was inversely proportional to the content of sub-boundaries after deformation. The distance between adjacent sub-boundaries determined the new grain size during continuous dynamic recrystallization, and a weight model was proposed for grain size prediction based on continuous rotation processing.
MATERIALS CHARACTERIZATION
(2023)
Article
Chemistry, Physical
Yu-Chi Xia, Xiao-Min Chen, Yong-Cheng Lin, Xian-Zheng Lu
Summary: The hot deformation characteristics of GH4169 superalloy were investigated, and the effects of deformation parameters on flow curves and annealing twins were discussed. It was found that the deformation temperature greatly affected the shapes of flow curves, and the evolution of annealing twins was sensitive to deformation degree, temperature, and strain rate.
Article
Chemistry, Physical
Yu-Qing Zhang, Guo-Zheng Quan, Jiang Zhao, Wei Xiong
Summary: This study investigates the improvement of mixed grain boundary network in a high-temperature alloy through a two-stage deformation method. The results show that prior cold deformation significantly affects the mixed grain boundary network and promotes the formation of sigma 3(n) twin boundaries.
Article
Materials Science, Multidisciplinary
Vishal Yadav, Nele Moelans, Yubin Zhang, Dorte Juul Jensen
Summary: The migration velocities of recrystallization boundaries depend on the spacing between planar geometrically necessary boundaries in the deformation microstructure, and the morphology of the deformation field strongly affects the migrating boundary during recrystallization. Two closely linked regimes were found based on simulations performed as a function of stored energy and GNB spacing independently.
Article
Engineering, Manufacturing
Nimel Sworna Ross, C. Gopinath, Srinivasan Nagarajan, Munish Kumar Gupta, Ragavanantham Shanmugam, M. Saravana Kumar, Mehmet Boy, Mehmet Erdi Korkmaz
Summary: Issues such as poor surface traits, short insert life, high manufacturing costs, and low productivity are commonly associated with the machining of nickel alloys. Research indicates that hybrid cooling/lubrication conditions considerably decrease temperature and specific cutting energy, reduce burr formation, and offer new advantages.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Article
Chemistry, Physical
Qiu-Mei Yang, Yong-Cheng Lin, Ming-Song Chen, Zi-Jian Chen
Summary: The features and evolution of microstructure of a new HIPed P/M superalloy are investigated through hot-compression tests. The study reveals the significant influence of deformation conditions on dynamic recrystallization (DRX) features and grain-growth behavior.
Article
Materials Science, Multidisciplinary
Xiao Lei, He Yingjie, Ma Xiangdong, Qiu Chuanrong, Yang Jinlong, Guo Jianzheng
Summary: This study conducted a series of hot extrusion tests on a novel powder metallurgy superalloy WZ-A3 to investigate the effects of extrusion temperature, speed, and ratio on the microstructure and uniformity of the extruded bar. The results revealed that under certain conditions, dynamic recrystallization occurred with grain coarsening. Moreover, the study found significant influences of extrusion temperature, speed, and ratio on the grain size and uniformity of the bar.
RARE METAL MATERIALS AND ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Bing Sun, Tiebang Zhang, Lin Song, Lei Zhang
Summary: This study investigates the microstructural evolution and dynamic recrystallization mechanism of a nickel-based superalloy PM EP962NP during isothermal compression at 1150 degrees C under different strain rates and strains. The results show that continuous dynamic recrystallization occurs when the strain exceeds 0.36. A processing window with high microstructure stability, including the evolution of DRX, y grains, and y' precipitates, is determined to be hot compression at 1150 degrees C with a strain rate of 0.001 s-1 and strains ranging from 0.69 to 1.20. In addition, the y' precipitates exhibit inhomogeneous sizes due to the interaction between dissolution and precipitation, with micron-scale blocky primary y' and nano-scale spherical secondary y'. Moreover, the abundant microstructural information related to the strain rates and strains can provide a reference for obtaining gradient microstructures through thermo-mechanical processes.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Multidisciplinary Sciences
Qi Zhu, Qishan Huang, Yanzhong Tian, Shuchun Zhao, Yingbin Chen, Guang Cao, Kexing Song, Yanjun Zhou, Wei Yang, Ze Zhang, Xianghai An, Haofei Zhou, Jiangwei Wang
Summary: This study investigates the intrinsic deformability of defective twin boundaries in metallic materials and finds that inherent kinks on twin boundaries can facilitate the formation of secondary and hierarchical nanotwins. This defect-driven hierarchical twinning propensity is critically dependent on the kink height and is generally applicable in various metals and alloys.