检索结果-南通市图书馆

Novel bake hardening mechanism for bainite-strengthened complex phase steel

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第12期143卷 117-128页

作者： Hang Yu Yu Yan Cheng Zhang lijie qiao Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Corrosion and Protection Center University of Science and Technology BeijingBeijing 100083China

In the automobile industry,stamping and paint baking processes are used to strengthen components,and this not only saves costs,but also further reduces the bodyweight of *** this work,the bake hardening mechanism of the complex phase(CP)steel CP980 was explored by comparing it with that of DP1180,which has a clear bake hardening mechanism and a carbon content similar to that of *** analyzing the bake hardening response and the microstructural changes of the two steels,we found that the bake hardening process of CP980 was divided into three *** the first two stages,the carbon atoms diffused into dislocations to form Cottrell atmosphere pinning dislocations,and excess car-bon atoms formed carbon clusters or low-temperature carbide pinning dislocations that were similar to *** the third stage,the dislocation acted as rapid channels for carbon diffusion,and fine cementite gradually formed when the carbon clusters gathered at the dislocations as precursors,resulting in pre-cipitation *** novel bake-hardening(BH)mechanism is crucial for obtaining a comprehensive understanding of the strain-baking behavior of advanced high-strength steals(AHSS).

关键词： Age hardening Bainitic steel Carbon diffusion Cementite Mechanical property Automotive weight reduction

Microstructure evolution of in-situ nanoparticles and its comprehensive effect on high strength steel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第9期35卷 1940-1950页

作者： Rongjian Shi Zidong Wang lijie qiao Xiaolu Pang Beijing Advanced Innovation Center for Materials Genome Engineering Beijing 100083China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Corrosion and Protection Center University o f Science and Technology BeijingBeijing 100083China

A novel steel strengthened by nanoparticles was investigated in this study. A Fe-based high-strength steel was developed by the trace-element regional supply method during deoxidization to generate in situ nanoparticles with a high number density in the matrix. The results show that the endogenous nanoparticles are aluminum oxide (AI2O3) and titanium oxide (Ti3O5) formed in the liquid melt. Al2O3 functioned as a heterogeneous nucleation site for MnS during solidification;the size of the resultant complex inclusions was approximately 1-2 jjim. Furthermore, 13 nm Nb(C,N) precipitates grew with the Ti30 5 during the tempering process. These in situ nanopartides strongly affected refining of the grain and inclusions. The investigated steel was strengthened more than 200 MPa by precipitation strengthening and more than 265 MPa by grain refinement strengthening according to the Ashby-Orowan mechanism and the Hall-Petch relationship, respectively.

关键词： In situ nanoparticles Titanium oxide Aluminum oxide Strengthening mechanism HSLA

Significant influence of trace Li on the mechanical properties, corrosion behavior, and antibacterial properties of biodegradable Zn–4Cu alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第20期151卷 245-257页

作者： Shiyu Huang Heng Liu Yanjing Su lijie qiao Yu Yan Beijing Advanced Innovation Center for Materials Genome Engineering Corrosion and Protection CenterInstitute for Advanced Materials and TechnologyUniversity of Science and TechnologyBeijing 100083China

In this work,trace Li was introduced to strengthen Zn–4Cu *** results indicated that trace amounts of Li contributed to a significant increase in strength,resulting in an acceptable loss of elongation at ***,Li in the form of LiZn_(4) led to more intensive galvanic corrosion,which accelerated the early corrosion *** release of a large amount of Zn^(2+),caused by the addition of Li,affected the phase composition of the main Zn-containing corrosion ***,the inhibition effect of the alloy on Staphylococcus aureus(***)was enhanced by the addition of 0.02 wt.%Li.

关键词： Microalloying Zn-Cu alloy LiZn_(4)/Zn pairs Biodegradable mechanism SKPFM

Investigation of stress corre-sion cracking under anodic dissolution control

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第9期46卷 717-722页

作者： Wuyang Chu lijie qiao Kewei Gao Univ Sci & Technol Beijing Dept Mat Phys Beijing 100083 Peoples R China

This review is about stress corrosion cracking (SCC) under anodic dissolution control. The section 1 is the methods distinguishing SCC controlled by anodic dissolution from those by hydrogen. The section 2 presents hydrogen-enhanced corrosion and SCC under anodic dissolution control. The section 3 demonstrates corrosion-enhanced localized plasticity and corrosion-induced deformation localization, which are the fundaments of new mechanism of SCC. The section 4 is an overview of the proposed mechanisms of SCC under anodic dissolution control. The last section proposes a new mechanism of SCC.

关键词： stress corrosion cracking hydrogen induced cracking dislocation.

Lifecycle of cobalt-based alloy for artificial joints:From bulk material to nanoparticles and ions due to bio-tribocorrosion

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第11期42卷 98-106页

作者： Zhongwei Wang Yu Yan Yang Wang Yanjing Su lijie qiao Beijing Advanced Innovation Center for Materials Genome Engineering Corrosion and Protection CenterKey Laboratory for Environmental Fracture(MOE)University of Science and Technology BeijingBeijing 100083China College of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054China Corrosion and Protection Center Advanced Institute for Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China

The release of debris and ions from metallic artificial joints during bio-tribocorrosion posed a severe threat to patient *** this work,the lifecycle of a Co Cr Mo alloy was presented by investigating the subsurface microstructure transformation *** results showed that the originally coarse grains changed to nano-grains(NGs)on the top region of the alloy,and nanoparticles(NPs)were torn off the surface,which were then blocked by the *** agglomerated alloy NPs contained in the tribofilm transformed into debris after being removed from the alloy *** majority of the torn-off NPs were corroded and released ions into solution due to their high chemical activities.

关键词： Cobalt-based alloy Artificial joints Wear mechanism Bio-t Ribocorrosion TEM

Corrosion form transition of mooring chain in simulated deep-sea environments:Remarkable roles of dissolved oxygen and hydrostatic pressure

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第31期162卷 118-130页

作者： Xuewei Zhang Weijie Wu Yuan Li Jinxu Li lijie qiao Corrosion and Protection Center Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China

The corrosion form and mechanical properties deterioration of mooring chain steel in simulated deep-sea environments were *** the increase of ocean depth,not only the pressure increases,but also the dissolved oxygen content *** two factors affect corrosion evolution of mooring chain steel in simulated deep-sea environments,which was studied for the first *** with uniform corrosion of mooring chain steel in shallow sea with sufficient oxygen,low dissolved oxygen leads to the corrosion dominated by pitting with pit ***,hydrostatic pressure distinctly accelerates pitting initiation and *** higher the hydrostatic pressure is,the more serious the pitting *** failure mechanism of unstressed mooring chain steel serving in simulated deep-sea environments,both absorbed hydrogen and corrosion morphology can degrade the ductility of mooring chain steel,in which the leading factor depends on the service *** severe pitting is the main factor and causes remarkable ductility loss of the steel after long-term *** hydrogen plays an important role on elongation loss in early stage.

关键词： High-strength low-alloy steel Dissolved oxygen Hydrostatic pressure Pitting corrosion Failure mechanism

Low-fired Y-type hexagonal ferrite for hyper frequency applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2012年第2期1卷 100-109页

作者： Yang BAI Wenjie ZHANG lijie qiao Ji ZHOU Key Laboratory of Environmental Fracture(Ministry of Education) University of Science and Technology BeijingBeijing 100083China State Key Lab of New Ceramics and Fine Processing Department of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Y-type hexagonal ferrite with planar magnetocrystalline anisotropy has ultrahigh cut-off frequency up to GHz and excellent magnetic properties in hyper frequency range,so that is regarded as the most suitable material in correpongding inductive devices and *** technology of low temperature cofired ceramics for surface-mounted multilayer chip components needs ferrite to be sintered well under 900℃to avoid the melting and diffusion of Ag inner electrode during the cofiring *** lower the sintering temperature of Y-type hexagonal ferrite,there are several methods,(1)using nano-sized starting powders,(2)substitution by low-melting elements,(3)adding sintering additives,and(4)introducing lattice *** this paper,the effects of different methods on the sintering behavior and the magnetic properties were discussed in detail.

关键词： hexagonal ferrite magnetic material low temperature cofiring ceramics

Study on delayed cracking of conductive notch under electric field in PZT-5H ferro- electric ceramics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第17期51卷 2146-2149页

作者： qiao Guangli SU Yanjing qiao lijie CHU Wuyang Department of Materials Physics University of Science and Technology Beijing Beijing 100083 China

Electric-field-induced delay cracking of conducting notch in PZT-5H ferroelectric ceramics has been studied using a compact specimen with a notch filled in conductive silver paste. The critical electric field that induces instant failure of the PZT-5H specimen is shown to be EF = 14.7±3.2 kV/cm. When an electric field lower than EF, but higher than EDF = 9.9 kV/cm was applied, a micro-crack formed at the conductive notch tip instantly, propagating slowly until the specimen failure. When the electric field was lower than EDF, the micro-crack propagated a short distance, and then stopped. When the electric field was lower than EK=4.9 kV/cm, no cracks formed at the conductive notch tip instantly, however, a delay micro-crack would form and propagate. When the electric field was lower than EDK=2.4 kV/cm, no cracks formed and delay propagation occurred. A model for electric charge emission and concentration at a conductive notch is proposed to explain the delay cracking of conducting notch.

关键词：铁电陶瓷 PZT 延迟裂纹电磁感应

Surface effects on static bending of nanowires based on non-local elasticity theory

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2015年第5期25卷 520-524页

作者： Quan Wu Alex A.Volinsky lijie qiao Yanjing Su Corrosion and Protection Center Key Laboratory for Environmental Fracture (MOE) University of Science and Technology Beijing Department of Mechanical Engineering University of South Florida

The surface elasticity and non-local elasticity effects on the elastic behavior of statically bent nanowires are investigated in the present investigation. Explicit solutions are presented to evaluate the surface stress and non-local elasticity effects with various boundary *** with the classical Euler beam, a nanowire with surface stress and/or non-local elasticity can be either stiffer or less stiff, depending on the boundary conditions. The concept of surface non-local elasticity was proposed and its physical interpretation discussed to explain the combined effect of surface elasticity and non-local elasticity. The effect of the nanowire size on its elastic bending behavior was investigated. The results obtained herein are helpful to characterize mechanical properties of nanowires and aid nanowire-based devices design.

关键词： Surface effect Non-local elasticity Nanowires Size effect Euler–Bernoulli beam