检索结果-南通市图书馆

Effect of secondary aging on microstructure and properties of cast Al-Cu-Mg alloy

在线全文

学校读者我要写书评

暂无评论

China Foundry 2023年第1期20卷 71-77页

作者： Rui-ming Su Yong-xin Jia Jian Xiao guang-long li Ying-dong Qu Rong-de li School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Guizhou Yonghong Aviation Machinery limited liability Company Guiyang 550009China

To obtain better comprehensive properties of cast Al-Cu-Mg alloys,the secondary aging(T6I6)process(including initial aging,interrupted aging and re-aging stages)was optimized by an orthogonal *** microstructures of the optimized Al-Cu-Mg alloy were observed by means of scanning electron microscopy and transmission electron microscopy,and the properties were investigated by hardness measurements,tensile tests,exfoliation corrosion tests,and intergranular corrosion *** show that the S phase andθ’phase simultaneously exist in the T6I6 treated *** increasing the temperature of the interrupted aging in the T6I6 process can improve the mechanical properties and corrosion resistance of Al-Cu-Mg *** optimal comprehensive properties(tensile strength of 443.6 MPa,hardness of 161.6 HV)of the alloy are obtained by initial aging at 180℃for 2 h,interrupted aging at 90℃for 30 min,and re-aging at 170℃for 4 h.

关键词： cast Al-Cu-Mg alloy secondary aging mechanical properties corrosion resistance strengthening phase

An innovative process of clad teeming for preparing slab ingot

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2022年第12期29卷 2006-2015页

作者： Wen-bin Ma Yao-hui Jin Yu-an Jing Wen-bin li Wei-da Yu guang-long li Wan-ming li School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina Iron and Steel Research Institutes of Ansteel Group Corporation Anshan 114001LiaoningChina

An innovative process of clad teeming was proposed to prepare slab ingot,which featured a built-in cold core to inhibit solidification defects.A 20-kg clad ingot was prepared in the experiment,using a volume ratio of solid core to molten steel of 1:13 and a preheating temperature of cold core of 573 *** microstructures of the clad ingot were analyzed by comparing with a reference ingot without cold *** morphologies and mechanical properties of the clad ingot were studied before and after hot *** effect of cold core on heat transfer and nucleation during the solidification in clad ingot was *** show that the solidification microstructures in the clad ingot are refined and homogenized *** grain size in the center of the reference ingot is 2–3 times greater than that of clad ingot,and there is almost no columnar grain in the clad *** interfacial shear strength reaches 318 MPa,which shows excellent metallurgical bonding at the interface of cold core and molten *** defects at the interface are eliminated,and interfacial shear strength reaches 426 MPa after hot rolling with a 68.4%total reduction *** experiment and analysis of this process are expected to provide a new idea to prepare large ingots with refinement and homogeneity at a low cost.

关键词： Clad teeming Steel ingot Grain refinement Interface Cold core Interfacial mechanical property

Effect of mold and core preheating temperature on corrosion resistance of casting Al-12Si alloy U-shaped cooling channel

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

China Foundry 2023年第3期20卷 218-224页

作者： guang-long li Jie Zhang Meng-yu Wang Rui-ming Su Yang Cao Ying-dong Qu School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Key Laboratory of light Metal Materials and Engineering at Universities of liaoning Province Shenyang University of TechnologyShenyang 110870China

Temperature has an important impact on the corrosion resistance of mold with cooling channels prepared by casting *** effect of preheating temperature of the mold and the carbon fiber core on the roughness and corrosion resistance of U-shaped cooling channels made of Al-12Si alloy was examined in *** experimental results suggest that as the preheating temperature increased from 273 K to 573 K,the roughness of the inner wall of the cooling channel reduced from 96.6μm to 77.0μ*** the preheating temperature continued to increase to 723 K,the roughness increased to 85.3μ*** wetting between the Al melt and the carbon fiber will reduce micro bubbles and waves on the channel wall as the preheating temperature rises,thereby reducing the ***,with the further increase of preheating temperature,it will increase the solidification time of the Al *** this time,the carbon fiber and Al melt will take more time to react,which increases the roughness of the channel wall to a certain *** results of exfoliation corrosion show that the larger roughness will aggravate exfoliation *** prolongation of high temperature reaction time between the carbon fiber and the Al melt will lead to the segregation of Si,which is easy to cause intergranular ***,reasonable preheating temperature has an important impact on the roughness and corrosion resistance of U-shaped cooling channels.

关键词： U-shaped cooling channels roughness exfoliation corrosion intergranular corrosion

Highly Improved Creep Resistance in Polypropylene Through Thermally Reduced Graphene Oxide and Its Creep lifetime Prediction

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第2期42卷 256-266,I0010页

作者： Can-Can Zhang Jun-long Yang Ya-Jiang Huang guang-Xian li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu610065China

Polypropylene(PP) exhibits suboptimal creep resistance due to the presence of methyl groups on its main chain, leading to irregular chain segment distribution, diminished inter-chain interaction, and crystallinity. This structural feature causes chain slippage in PP under stress,significantly constraining its service lifetime. In this study, thermally reduced graphene oxide(TrGO) nanosheets were incorporated into the PP matrix, yielding a nanocomposite with exceptional creep resistance performance. Results demonstrated that at a stress of 25 MPa, a 2.0 wt% TrGO content could enhance the creep failure lifetime of PP by 21.5 times compared to neat PP. Rheology, transmission electron microscopy(TEM),and scanning electron microscopy(SEM) characterization techniques were employed to analyze the mechanism of TrGO's influence on PP's creep behavior. It was observed that when TrGO content exceeded 1.0 wt%, an effective particle network structure formed within the PP matrix. This homogeneously dispersed TrGO-formed particle network structure restricted the migration and rearrangement of PP molecular chains, enabling prolonged stress resistance without structural failure. By combining the time-strain superposition method with the critical failure strain as a criterion, generalized creep compliance curves for PP and its composites were established, facilitating the prediction of material creep failure lifetimes, with a strong agreement between experimental and predicted lifetime values. This research proposes a novel strategy aimed at developing polypropylene materials and products with enhanced long-term stability and durability, thus extending service life, reducing failure risk, and broadening their potential across various application domains.

关键词： Thermally reduced graphene oxide Polypropylene Creep failure and lifetime prediction

Atomic-scale mechanism of effect of co-separation of elements at interface of ferrite and austenite on Cr-depleted zone of duplex stainless steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第3期31卷 710-718页

作者： Yan-hui Hou Ze-kun Xu Shi-long Zhou guang-qiang li The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Three-dimensional atom-probe tomography and first-principles calculation combined with density functional theory were used to study the effect of the co-segregation of different elements formed during the solidification process of S32205 duplex stainless steel on the Cr-depleted zone at the interface between ferrite and *** was found that the co-segregation of different elements formed during the solidification process of duplex stainless steel can also form Cr-depleted zone at the interface between ferrite and ***,Mo,Si,B,C and P atoms promote co-segregation with Cr atoms,which promotes the formation of Cr-depleted zone at the interface between ferrite and austenite in duplex stainless *** and Si strongly promote the segregation of Cr at the interface between ferrite and austenite,thereby promoting the formation of Cr-depleted zone.B,C and P elements also promote the segregation of Cr element at the interface between ferrite and austenite and the formation of Cr-depleted zone,but their effect is weaker than that of Mo and Si *** conclusions provide a new theoretical basis for improving the intergranular corrosion performance of duplex stainless steel.

关键词： Duplex stainless steel Cr-depleted zone Intergranular corrosion Co-segregation First-principles calculation

Effect of V and Sn on microstructure and mechanical properties of gray cast iron

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

China Foundry 2022年第5期19卷 427-434页

作者： Yi-li li Rui-run Chen Qi Wang Wen-chao Cao Xin-xiu Wang Yuan Xia Guo-ping Zhou Ying-dong Qu guang-long li School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Yangzhou Wutingqiao Cylinder liner Co. Ltd.Yangzhou 225000JiangsuChina School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China

The cylinder liner is one of the important parts of a diesel *** cast iron is the main material for manufacturing cylinder liners due to its good casting performance,convenient processing performance,good wear resistance and low *** the present work,the effects of vanadium(V)and tin(Sn)on the microstructure and properties of gray cast iron were *** show that increasing the contents of V and Sn can not only refine the graphite,but also reduce the pearlite lamellar *** graphite size and lamellar spacing of pearlite are firstly reduced and then *** quantity reaches over 98%after adding V and *** V and Sn can promote the precipitation and solid solution strengthening of gray cast iron,so as to improve the mechanical *** Brinell hardness reaches the peak of 424 HB at the contents of 0.21wt.%V and 0.06wt.%Sn,and the sample containing 0.11wt.%V and 0.08wt.%Sn shows the highest compressive strength and tensile strength of 1,699 MPa and 515 MPa,*** main strengthening mechanism comes from the solid solution strengthening and fine grain strengthening of V and Sn.

关键词： V Sn gray cast iron cylinder liner microstructure mechanical properties

Effect of TiO_(2)nano-ceramic particles on microstructure and mechanical properties of Al_(0.4)CoCrFe_(2)Ni_(2)high-entropy alloy

在线全文

学校读者我要写书评

暂无评论

China Foundry 2022年第6期19卷 528-534页

作者： Hao Qi guang-long li Wei Zhang Qing-yao Lü Rong-de li Si-chen Xie Yu Shi Bo Yu Rui-run Chen Ying-dong Qu School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China State Key Laboratory of light Alloy Casting Technology for High-end Equipment Shenyang Research Institute of Foundry Co.Ltd.Shenyang 110022China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

Al_(0.4)CoCrFe_(2)Ni_(2)high-entropy alloys with different additions of TiO_(2) nanoceramic particles(0,1.25vol.%,2.5vol.%,3.75vol.%and 5vol.%,respectively)were prepared by using the vacuum arc melting *** effects of TiO_(2) addition on the crystal structure,microstructures and mechanical properties of the alloy were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and tensile *** microstructure analysis shows that the TiO_(2)nano-ceramic particles added in the alloy are decomposed,and a small amount of Al_(2)O_(3)and a great number of intermetallic compounds(γ'phases)with simple cube structure are ***γ'phases are enriched at inter-dendrite,which increases the resistance of dislocation movement during the deformation of the alloy,thus balancing the problem of high plasticity and low strength of the *** the addition of TiO_(2)is 2.5vol.%,the strength of the high-entropy alloy reaches the maximum of 489 MPa,which is 11.1%higher than the matrix alloy composed of single FCC phase.

关键词： high-entropy alloy TiO_(2)nano-ceramic particles microstructure mechanical property

Highly Hydrolysis-Resistant Polyimide Fibers Prepared by Thermal Crosslinking with Inherent Carboxyl Groups

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第2期42卷 247-255,I0010页

Easy hydrolysis in alkaline environments limits the use of polyimide fibers in environmental protection. The hydrolysis resistance levels of polyimide fibers can be improved by crosslinking of the macromolecular chains. In this work, crosslinked polyimide fibers(CPI fibers) were produced by intrinsic carboxyl decarboxylation for the first time. The thermal stability of the polyimide fibers containing the intrinsic carboxyl groups(PIC fibers) was studied, and the temperature of the decarboxylation-crosslinking reaction was determined to be 450 ℃. The PIC fibers were hotdrawn to initiate thermal crosslinking of the carboxyl groups and molecular chain orientation at high temperature. The CPI fibers had high tensile strengths(0.72-1.46 GPa) and compressive strengths(401-604 MPa). The oriented macromolecules and chemically crosslinked structure improved the tightness of the molecular chains and endowed the CPI fibers with excellent hydrolytic resistance. The CPI-50 fiber did not dissolve in a 0.5 wt% NaOH solution during heating at 90 ℃ for 10 h, and the tensile strength retention reached 87% when treated in 0.5 wt% NaOH solutions at 90 ℃ for 1 h, providing a guarantee for its application in alkaline corrosive environments.

关键词： Polyimide Carboxyl group Crosslinking Hydrolysis-resistance

Congener-derived template to construct lithiophilic organic-inorganic layer/interphase for high volumetric capacity dendrite-free li metal batteries

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第3期35卷 453-460页

作者： Kang Yang long li Yuanbin Xiao Qiaoli Zhang Chenpeng Xi Borong li Yan Yu Chengkai Yang Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China

The development of lithium-metal batteries(LMBs)is seriously restricted by the out-of-control dendrites growth and infinite volume ***,a pervasive organic-inorganic layer construction strategy is reported for the composite lithium metal anode with congener-derived organic-inorganic solid electrolyte interphase(SEI).In this strategy,the organic-inorganic Ag@polydopamine(Ag@PDA)layer is coated on the arbitrary substrates by a simple two-step *** thin and stable congener-derived SEI is insitu formed with fewer inorganic components and more organic components during charging/*** polydopamine with sufficient adhesion groups and lithiophilic Ag layer realize near-zero nucleation overpotential during lithium *** low interface resistance and stable lithium deposition are ***,the practical areal and volumetric capacities of the composite anode with three-dimensional copper(3DCu)as the substrate are 10 mAh/cm^(2)and 1538 mAh/cm^3(*** mass of anode).The symmetrical cell shows very low polarization voltage(10 mV)and more than 2500 h cycles life at 1 mA/cm^(2)(1 mAh/cm^(2)).The liNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)-based full cells show improved capacity retention(82%)after 100 cycles at 0.5 *** modified lithiophilic anode with congener-derived interphase provides a promising strategy to realize the next-generation dendrite-free LMBs.

关键词： lithium metal anode Congener-derived lithiophilicity Volumetric capacity Organic-inorganic interphase