检索结果-南通市图书馆

Impact of cooling rate on mechanical properties and failure mechanism of sandstone under thermal-mechanical coupling effect

引用

International Journal of Coal Science & Technology 2023年第2期10卷 97-116页

作者： Pingye Guo Peng Zhang Mohua Bu Hang Xing Manchao He State Key Laboratory for Geo-Mechanics and Deep Underground Engineering Beijing 100083China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing 100083China

High geo-temperature is one of the inevitable geological disasters in deep engineering such as resource extraction,space development,and energy utilization.One of the key issues is to understand the mechanical properties and failure mechanism of high-temperature rock disturbed by low-temperature airflow after excavation.Therefore,.the experimental and numerical investigation were carried out to study the impact of cooling rate on mechanical properties and failure mechanism of high temperature sandstone.First,uniaxial compression experiments of high temperature sandstone at different real-time cooling rates were carried out to study the mechanical properties and failure modes.The experimental results indicate that the cooling rate has a significant effect on the mechanical properties and failure modes of sandstone.The peak strain,peak stress,and elastic modulus decrease with an increase in cooling rate,and the fragmentation degree after failure increases gradually.Moreover,the equivalent numerical model of heterogeneous sandstone was established using particle flow code(PFC)to reveal the failure mechanism.The results indicate that the sandstone is dominated by intragrain failure in the cooling stage,the number of microcracks is exponentially related to the cooling rate,and the higher the cooling rate,the more cracks are concentrated in the exterior region.Under axial loading,the tensile stress is mostly distributed along the radial direction,and the damage in the cooling stage is mostly due to the fracture of the radial bond.In addition,axial loading,temperature gradient and thermal stress mismatch between adjacent minerals are the main reasons for the damage of sandstone in the cooling stage.Moreover,the excessive temperature gradient in the exterior region of the sandstone is the main reason for the damage concentration in this region.

关键词： High geo-temperature Thermo-mechanical coupling effect cooling rate Sandstone PFC

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effect of cooling rate on Microstructure and Effective Grain Size for a Ni–Cr–Mo–B High-Strength Steel

引用

Acta Metallurgica Sinica(English Letters) 2022年第11期35卷 1862-1872页

作者： Shouqing Zhang Xiaofeng Hu Haichang Jiang Lijian Rong CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The effect of cooling rate on microstructure and effective grain size(EGS)of a Ni-Cr-Mo-B high-strength steel has been studied by dilatometer,field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM)and electron backscattered diffraction(EBSD).The results show that the microstructure of the Ni-Cr-Mo-B steel is dependent on cooling rate in the following sequence:lath martensite(LM),mixed LM and lath bainite(LB),mixed LB and granular bainite(GB)and GB.The critical cooling rates for appearance of LB and GB are about 10℃/s and 0.5℃/s,respectively.The LM(>10℃/s)consists of few blocky regions with a width of several micros.Compared with the lath regions,the blocky regions in LM form at higher actual transformation temperatures during cooling.The blocky region area percentage in LM keeps almost constant about 8%at different cooling rates(>10℃/s)due to similar martensite transformation starting temperature(M_(s)).The LB percentage in mixed LM/LB increases gradually with decreasing cooling rate(10-0.5℃/s).The EBSD results show that different microstructures have different EGS.The mixed LM/LB exhibits the smallest EGS due to the separation of the prior austenite grains by the pre-formed LB and the refinement of the LM.Meanwhile,the mixed LM/LB at different cooling rates(10-0.5℃/s)exhibits almost the same EGS because the LB and LM in the mixed LM/LB have a similar high-angle grain boundary density and similar EGS.Because the blocky regions contain few high-angle grain boundaries and have similar area percentages in the LM,the LM at different cooling rates(>10℃/s)exhibits almost the same EGS.The ferrite in GB exhibits as a whole with few high-angle grain boundaries;thus,the mixed LB/GB exhibits the largest EGS.

关键词： Ni–Cr–Mo–B steel cooling rate Microstructural characterization Effective grain size(EGS)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of cooling rate followingβforging on texture evolution and variant selection duringβ→αtransformation in Ti-55511 alloy

引用

Journal of Materials Science & Technology 2022年第18期113卷 1-13页

作者： Yue Dong Xingang Liu Junjie Zou Yujiao Ke Pengwei Liu Lan Ma Hengjun Luo College of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Oxford Instruments(Shanghai)Co. Ltd.No.461Hongcao RoadShanghai 200233China Deyang Wanhang Die Forging Co. Ltd.China National Erzhong Group Co.Deyang 618000China

The control of the post-forging cooling rate has been a key issue in the industrial production process of titanium alloys. We investigated texture evolution and variant selection(VS) during β → α transformation through high-temperature compression experiments followed by quantitative control of varying cooling rates. Results show that post-forging cooling rates affect β grains, α variants, and α/β textures. The αprecipitation inhibits motions of β static recrystallization(β_(SRX)) grain boundaries and thus leads to grain refining from 0.1 ℃/s to 0.05 ℃/s. Further analysis reveals that lamellae grain boundary widmanstattenα(α_(WGB)) keeps growing rapidly within β-grain in an interface instability manner at 0.1–0.05 ℃/s. Most of α-phase with 50°–60°/ is preferentially precipitated at β-medium angle GBs between 30°and 45° and strictly follows BOR with the side of of adjacent β-grain with the same or similar {110} or{111}. Moreover, the texture type transforms gradually from RGoss {110} to Brass {110} from 25 ℃/s to 1 ℃/s. βgrains exhibit(102) [-201] texture, while the corresponding α has textures of//Z and //Y from 1 ℃/s to 0.05 ℃/s. Our findings lay a profound theoretical foundation in microstructure evolution of near-β titanium alloy for industrial production.

关键词： Ti-55511 alloy cooling rate Texture evolution Phase transformation Variant selection(VS)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of cooling rate on microstructure and crystallographic characters for Fe3O4 seam-free on J82B steel from 650°C

引用

Progress in Natural Science:Materials International 2023年第5期33卷 718-732页

作者： Junyang Wang Jinwen Mu Shanhong Wan Gewen Yi Jun Jiang Xianglong Yu Xinlong Yang State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Jiugang Hongxing Iron & Steel Co.Ltd. State Key Laboratory of Tribology Department of Mechanical Engineering Tsinghua University

Surface quality and tensile strength are required for the deep processing yield of high-carbon steel wires,particularly those with a cumulative reduction rate above 60 %. A systematic investigation was conducted to discern the influence mechanism of cooling rate on microstructure and crystallographic characteristics for the matrix from 650°C. The results show that the microstructure of the sample cooled at 1.5°C/s consists of a single pearlite, and the grain orientation is mainly the easy sliding crystal plane {101}. The retained austenite/martensite microstructure appears and grows with the cooling rate increasing to 4.5 and 7.5°C/s. The grain orientation shifts from an easy slip {101} plane orientation to hard slip {001} and {111} plane orientations. The number of high-angle grain boundaries that inhibit crack expansion decreased. In addition, the number of twin boundaries in the austenite/martensite grains increased. An increase in the cooling rate increased the material hardness and decreased the plastic toughness. Therefore, the cooling rate of 1.5°C/s from 650°C might concurrently yield the optimal surface quality and the microstructure of the matrix during steel production.

关键词： 3500 gleeble thermal simulator cooling rate EBSD Fe3O4 seam layer High carbon steel wire Matrix microstructure

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

cooling rate Dependence of Structural Order and Energy Landscape in Zr_(55)Cu_(35)Al_(10) Glass

引用

Journal of Harbin Institute of Technology(New Series) 2022年第5期29卷 78-85页

作者： Jingfeng Zhao Xiangxu Xie Feng Chen Kailong Di Xuefeng Zhou School of Materials Engineering Changshu Institute of TechnologyChangshu 215500JiangsuChina

Classical molecular dynamics simulation has been widely used to study the rapid cooling process of preparing amorphous alloys.However,the simulated cooling rate is several orders of magnitude higher than the experimental cooling rate.In this paper,Zr_(55)Cu_(35)Al_(10)alloy was taken as an example.It is found that adding isothermal annealing at a temperature slightly lower than Tand prolonging isothermal annealing time could effectively reduce the cooling rate.The glassy sample prepared in this way demonstrates significant energetic stability and well-developed short-range and medium-range order.

关键词： classical molecular dynamics simulation cooling rate isothermal annealing energetic stability short-range order medium-range order

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The effects of deformation parameters and cooling rates on the aging behavior of AZ80+0.4%Ce

引用

Journal of Magnesium and Alloys 2024年第2期12卷 639-658页

作者： Yongbiao Yang Jinxuan Guo Cuiying Wang Ting Yan Zhang Wenxuan Jiang Zhimin Zhang Qiang Wang Guojun Li Jun Wang College of Materials Science and Engineering North University of ChinaLane 3Xueyuan RoadTaiyuanShanxiChina030051 State Key Laboratory of Advanced Stainless Steel Materials Taiyuan Iron Steel(Group)Co.Ltd.Taiyuan 030003China Technology Center Shanxi Taigang Stainless Steel Co.Ltd.Taiyuan 030003China

The extruded AZ80+0.4%Ce magnesium alloy was twisted in the temperature range of 300-380℃by using a Gleeble 3500 thermal simulation test machine with a torsion unit.The deformed cylindrical specimens were cooled at a cooling rate of 10℃/s or 0.1℃/s,respectively,and aged at 170℃.The microstructure analysis results showed that the grain size decreased with increasing specimen radial position from center(SRPC),and that the strong initial basal texture of the extruded magnesium alloy was weakened.Both continuous and discontinuous dynamic recrystallization mechanisms were involved in contributing to the grain refinement for all specimens investigated.And a novel extension twinning induced dynamic recrystallization mechanism was proposed for specimen deformed at 300℃.For the specimens deformed at 300℃and 340℃followed by a slow cooling rate(0.1℃/s),precipitates of various shapes(β-Mg_(17)Al_(12)),with the dominant precipitates being on the grains boundaries,appeared on the surface section.For specimen deformed at 380℃,lamellar precipitates(LPS)in the interiors of the grains were predominant.After aging,the LPS still dominated for specimens twisted at 380℃;however,the LPS gradually decreased with decreasing deformation temperatures from 380℃to 300℃.Dynamically precipitatedβ,especially those decorating the grain boundaries,changed the competition pictures for the LPS and precipitates of other shapes after aging.Interestingly,LPS dominated the areas for the center section of the specimens after aging regardless of deformation temperatures.Low temperature deformation with high SRPC followed by rapid cooling rate increased the micro hardness of the alloy after aging due to refined grain,reduced precipitates size,decreased lamellar spacing as well as strain hardening.

关键词： AZ80+0.4%Ce magnesium alloy Hot torsion Deformation parameters cooling rate Aging Micro hardness

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

cooling rate controlled basal precipitates and age hardening response of solid-soluted Mg-Gd-Er-Zn-Zr alloy

引用

Journal of Magnesium and Alloys 2021年第4期9卷 1267-1277页

作者： Jinlong Fu Wenbo Du Linyue Jia Yunfeng Wang Xunming Zhu Xian Du Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China Weihai Wanfeng Magnesium S&T Development Co.LTD 264200China

The precipitation and age hardening response of the solid-soluted Mg–10Gd–1Er–1Zn–0.6Zr(wt.%)alloy performed by water-quenching(QC),air-cooling(AC)and furnace-cooling(FC)in terms of the volume fraction of precipitates and tensile properties were investigated in present paper.Results indicated the solid-soluted alloy contained stacking faults(SFs)and long period stacking ordered(LPSO)phase on the basal planes regardless of the cooling rate,but a larger volume fraction of the LPSO phase was formed with decreasing in the cooling rate.After aging,βandβ1 phases precipitated on the prismatic planes,and their number density decreased but mean particle size increased with decreasing in the cooling rate.The solid-soluted alloys(QC,AC and FC samples)showed no apparent difference in yield strength(YS),but their correspondent peak-aged alloys exhibited sharp difference in hardening response.The strongest hardening response took place in the QC sample and showed 82MPa enhancement in YS,which was much larger than that of AC(+26MPa)and FC samples(+5MPa).The reason lies in that the higher cooling rate promotes the precipitation and reduces the average size ofβprecipitate.A novel cooling-rate controlled precipitation model with respect to the correlation of precipitates on basal and prismatic planes was established.From this model,the basal precipitates showed a restrictive effect on the growth and/or coarsening ofβprecipitate,and composite precipitates containing theβphase with fine size as well as high area-number density and lower volume fraction of the LPSO phase are preferred to strengthen the Mg–10Gd–1Er–1Zn–0.6Zr alloy.

关键词： Magnesium alloy Long period stacking ordered(LPSO) Stacking faults(SFs) cooling rate Tensile properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of cooling rate on the 3D morphology of the proeutectic Al3Ni intermetallic compound formed at the Al/Ni interface after solidification

引用

Journal of Materials Science & Technology 2021年第10期69卷 60-68页

作者： Liao Yu Qiaodan Hu Zongye Ding Fan Yang Wenquan Lu Naifang Zhang Sheng Cao Jianguo Li Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Materials The University of ManchesterOxford RoadManchesterMl 39PLUK

Effect of cooling rate on the 3 D morphology and the growth mechanism of the proeutectic Al3Ni intermetallic compound(IMC) that forms at the Al/Ni interface after solidification was investigated by synchrotron X-ray microtomography in combination with EBSD analysis. The proeutectic Al3Ni phase that forms under an average cooling rate of 0.1 Ks^(-1) shows a characteristic faceted growth behavior and presents a typical 3 D morphology as partially hollow quadrangular prisms. On the contrary, that forms under an average cooling rate of 10 Ks^(-1) shows complicated dendritic morphology with asymmetrically distributed arms and faceted V-shape groove at the distal end, indicating a gradual transition of the growth behavior from non-faceted to faceted during the solidification process. These results reveal that the morphology of the proeutectic Al3Ni is highly sensitive to the solidification condition so that fine control of the desired morphology may be achieved by carefully manipulating the cooling profile.

关键词： 3D morphology Al3Ni intermetallic compounds Solidification cooling rate Synchrotron radiation Al/Ni interface

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microstructural characterization of Cu/Al composites and effect of cooling rate at the Cu/Al interfacial region

引用

International Journal of Minerals,Metallurgy and Materials 2015年第1期22卷 94-101页

作者： Yan-qiu Han Li-hua Ben Jin-jin Yao Chun-jing Wu School of Materials Science and Engineering University of Science and Technology Beijing

Cu/Al composites are of vital importance in industrial applications because of their numerous advantages. The influence of bond-ing temperature and cooling rate on the microstructure and morphology of Cu/Al composites was investigated in this paper. The interfacial morphology and constituent phases at the Cu/Al interface were analyzed by optical microscopy and field-emission scanning electron mi-croscopy equipped with energy-dispersive X-ray spectroscopy. The results indicate that effective Cu-Al bonding requires a higher bonding temperature to facilitate interdiffusion between the two metals. The microstructural characteristics are associated with various bonding tem-peratures, which impact the driving force of interdiffusion. It is observed that cooling rate exerts a significant influence on the morphology and amount of the intermetallic compounds at the interfacial region. Meanwhile, microhardness measurements show that hardness varies with the bonding temperature and rate of cooling.

关键词： composite materials copper aluminum temperature cooling rate interfaces diffusion bonding

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect on microstructure and plastic deformation behavior of a Zr-based amorphous alloy by cooling rate control

引用

Journal of Materials Science & Technology 2021年第23期82卷 1-9页

作者： Feilong Wang Dawei Yin Jingwang Lv Shan Zhang Mingzhen Ma Xinyu Zhang Riping Liu State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004China

In this study,Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5) amorphous alloys samples with the same diameter(8 mm)were prepared by using self-designed molds(viz.refractory steel,pure graphite,and copper molds)with different cooling capacities.Moreover,by eliminating the size effect,the effect of the cooling rate on the microstructure and compression deformation behavior of Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5) amorphous alloys was investigated.Differentiation of the cooling curves revealed that the instantaneous cooling rates of the alloy melt at the glass transition temperature(Tg)are 45,52,and 64 K·s^(-1) for refractory steel,pure graphite,and copper molds,respectively.X-ray diffraction,differential scanning calorimetry,and highresolution transmission electron microscopy analysis revealed that with the decrease in the cooling rate,trace icosahedral-like atomic clusters and nanocrystals appear in local areas of the amorphous alloy and that the amount of free volume decreases with the increase in the amount of icosahedra-like atomic clusters and nanocrystals.Compression test results revealed that the elastic strain,yield strength,and compressive strength of the amorphous alloy marginally change with the decrease in the cooling rate,while the plastic strain gradually increases.By fitting,the effective size of the vein-like pattern was linearly related to the enthalpy released during structural relaxation and plastic strain,indicating that at a low cooling rate,the trace nanocrystals in the amorphous alloy could not effectively improve its plasticity and that the amount of free volume mainly affects its plasticity.

关键词： Bulk amorphous alloy cooling rate Compression plasticity Free volume

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：