Article
Chemistry, Physical
Lihua Zhu, Hao Pan, Junyi Cheng, Lei Xiao, Jianzheng Guo, Hongjun Ji
Summary: The effect of cooling rate after super-solvus heat treatment on the morphological evolution of gamma' precipitates in an advanced powder metallurgy Ni-based superalloy was investigated. The relationship between cooling rate and gamma' precipitates was quantitatively analyzed. The results showed that cooling rate influenced the primary and secondary dendritic orientations of gamma' precipitates. Additionally, the width of the gamma' channel and the cooling rate affected the morphology and evolution of the gamma' precipitates.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Chiwon Kim, Jiun Park, Hyun-Uk Hong, Jiho Gu, Youngseok Song
Summary: The effects of stabilization conditions on microstructure evolution and mechanical properties of Ni-Fe-based superalloy Inconel 706 were investigated. The results showed that increasing the stabilization temperature led to an increase in precipitates and improved yield strength. Furthermore, the high temperature stabilization resulted in higher creep strain in the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Xipeng Tao, Yunling Du, Xinguang Wang, Jie Meng, Yizhou Zhou, Jinguo Li, Xiaofeng Sun
Summary: The impact of solution cooling rate on the microstructure and creep behavior of a novel single-crystal superalloy was studied. The results showed that the cubic degree and size of the gamma' phases were inversely proportional to the cooling rate, and the creep life first increased and then dropped dramatically with a reduction in the cooling rate. The sample cooled with air cooling exhibited the highest creep life, which was attributed to the fine cubic gamma' phases and the formation of dense gamma/gamma' interface dislocation networks.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Zhen Xu, Zhiwei Lv, Chuan Guo, Yang Zhou, Gan Li, Xiaogang Hu, Xinggang Li, Qiang Zhu
Summary: The steady-state creep mechanisms of a superlattice gamma'-strengthened Co-Al-W-Ta-Ti single crystal superalloy were studied under different temperature and stress conditions. The microstructures of the creep samples varied significantly according to the experimental conditions. Lomer-Cottrell locks and stacking faults interactions dominated the low-temperature and high-stress creep regime, while dislocations cross-slip and dislocation tangles contributed to the main creep resistance at intermediate temperatures and moderate stresses. The interactions of stacking faults and dislocation networks were the strengthening mechanism for the high-temperature and low-stress creep regime. The steady-state creep rate followed a classical power law equation, with a calculated creep activation energy of 378.46 kJ/mol. These findings provide insights into the effects of temperature and stress on steady-state creep mechanisms, and highlight the potential of the gamma'-strengthened Co-Al-W-Ta-Ti single crystal superalloy as a high-temperature structural material.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Wu Jinping, Li Chunchen, Zhao Bin, Qiu Longshi, Xin Chao, Pan Xiaolong, Zhao Heng, Li Huan, Zhao Jing
Summary: The relationship between creep behavior and microstructure of metal films at room temperature was evaluated through nanoindentation experiments. The results showed that the creep behavior of different metal films is influenced by the loading strain rate and different dominant deformation mechanisms, including screw dislocation movement, grain boundary emission incomplete dislocation, and shear deformation transition zone.
RARE METAL MATERIALS AND ENGINEERING
(2022)
Article
Engineering, Mechanical
Yonghun Yu, Junho Suh
Summary: By developing a three-dimensional thermo-elastic model and conducting numerical analysis and verification, this study investigated the interaction of mechanical and thermal deformation in steady-state rolling contact. The experimental results confirmed that under severe rolling conditions, the thermal effect significantly changes the behavior of the contact interface.
Article
Materials Science, Multidisciplinary
Christian Voelter, Joachim Roesler
Summary: This study investigates the production of porous structures from nickel-based superalloys through the coarsening of gamma'-precipitates and selective extraction of phases. Two approaches, directional and incoherent coarsening, can achieve a bicontinuous gamma/gamma'-microstructure. In this paper, the growth and coalescence of precipitates during initial slow cooling were studied, revealing that despite high gamma' content and small distance, little coalescence of particles occurs. Loss of coherency during coarsening must progress through further aging for the formation of a bicontinuous microstructure.
Article
Construction & Building Technology
B. B. Teltayev, A. I. Iskakbayev, B. D. Abu
Summary: This article investigates the steady-state deformation rate of asphalt concrete under various stress and temperature conditions. The study reveals that the steady-state deformation rate follows a power function with the stress and establishes important equations and expressions to describe this phenomenon.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Multidisciplinary
Jun Cao, Ke Wang, Weifeng Ma, Junjie Ren, Hailiang Nie, Wei Dang, Xiaobin Liang, Tian Yao, Xiaohan Zhao
Summary: Creep failure of in-service pipes is an important engineering issue, and the girth weld joint is a weak link. This study investigates the local creep properties and mechanisms of the X70 girth weld through experiments and microstructure analysis.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2022)
Article
Materials Science, Multidisciplinary
Jae-Yeon Kim, Jai-Won Byeon
Summary: This study systematically investigated the effects of discontinuous and continuous Mg17Al12 precipitates on the corrosion resistance of AZ91D magnesium alloy. The research found that the connectivity of the precipitates plays a crucial role in determining the corrosion resistance, with low connectivity accelerating corrosion and high connectivity acting as a corrosion barrier. Additionally, finely precipitated CPs inside the alloy grains consistently acted as a corrosion barrier, leading to reduced corrosion rates as connectivity increased.
MATERIALS CHARACTERIZATION
(2021)
Article
Crystallography
Jiapeng Huang, Cheng Ai, Yi Ru, Yong Shang, Yanling Pei, Shusuo Li, Shengkai Gong, Heng Zhang
Summary: This study investigated the effect of cooling rate on the microstructure and creep properties of Ni-based single crystal superalloys, and found that increasing the cooling rate can reduce the size of the gamma ' reprecipitates, change their morphology, and decrease lattice misfit, which helps to suppress coarsening of the gamma ' phase and reduce the precipitation of the TCP phase.
Review
Physics, Multidisciplinary
Chen Liu, Suman Dutta, Pinaki Chaudhuri, Kirsten Martens
Summary: The authors developed a framework to study the mechanical response of athermal amorphous solids by coupling mesoscale and microscopic models. They presented a coherent elastoplastic model approach for deformation and flow of yield stress materials using measurements of coarse-grained quantities from simulations. This model allows matching transient and steady state features of driven disordered systems with diverse preparation histories consistently.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Wanshun Xia, Xinbao Zhao, Quanzhao Yue, Liang Yue, Jiangwei Wang, Qingqing Ding, Hongbin Bei, Ze Zhang
Summary: The chemical and structural evolution of dislocation networks in a nickel-based single crystal superalloy under high temperature and pressure conditions were investigated in this study. The formation mechanism of γ'(n) phase and the significance of γ/γ' substructures in stabilizing dislocation networks were revealed.
Article
Metallurgy & Metallurgical Engineering
Jinlong Fu, Wenbo Du, Linyue Jia, Yunfeng Wang, Xunming Zhu, Xian Du
Summary: The solid-soluted Mg-10Gd-1Er-1Zn-0.6Zr alloy exhibited stacking faults and long period stacking ordered phase on the basal planes, with a higher volume fraction of the LPSO phase formed at lower cooling rates. Different cooling rates also influenced the precipitation and tensile properties of the alloy, with the water-quenched sample showing the strongest hardening response.
JOURNAL OF MAGNESIUM AND ALLOYS
(2021)
Article
Materials Science, Multidisciplinary
Luciano Eliezer Ramirez-Vidaurri, Manuel Castro-Roman, Martin Herrera-Trejo, Karla-Leticia Fraga-Chavez
Summary: The solidification evolution of an ASTM F75 alloy during directional cooling was studied, revealing that the solid grows most rapidly in a temperature range of approximately 200 degrees Celsius, reaching a solid fraction of about 0.8-0.9, with the coarsening of Secondary Dendrite Arm Spacing (SDAS) mainly occurring during this period.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)