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Study of extrudability and standoff distance effect during nanoclay-enabled direct printing 被引量:2
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作者 Yifei Jin Danyang Zhao Yong Huang 《Bio-Design and Manufacturing》 2018年第2期123-134,共12页
Nanoclay-enabled self-supporting printing has been emerging as a promising filament-based extrusion fabrication approach for different biomedical and engineering applications including tissue engineering. With the add... Nanoclay-enabled self-supporting printing has been emerging as a promising filament-based extrusion fabrication approach for different biomedical and engineering applications including tissue engineering. With the addition of nanoclay powders, liquid build materials may exhibit solid-like behavior upon extrusion and can be directly printed in air into complex three-dimensional structures. The objective of this study is to investigate the effect of nanoclay on the extrudability of N-isopropylacrylamide (NIPAAm) and the effect of standoff distance on the print quality during nanoclay-enabled direct printing. It is found that the addition of nanoclay can significantly improve the NIPAAm extrudability and effectively eliminate die swelling in material extrusion. In addition, with the increase of standoff distance, deposited filaments change from over-deposited to well-defined to stretched to broken, the filament width decreases, and the print fidelity deteriorates. A mathematical model is further proposed to determine the optimal standoff distance to achieve better print fidelity during nanoclay-enabled direct printing. Based on the extrudability and standoff distance knowledge from this study, NIPAAm-Laponite nanoclay and NIPAAm-Laponite nanoclay-graphene oxide nanocomposite hydrogel precursors are successfully printed into a three-layered one-dimensional responsive pattern, demonstrating the good extrudability and print quality during nanoclay-enabled printing under optimal printing conditions. 展开更多
关键词 extrudability Print quality NANOCLAY Standoff distance Direct printing
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Investigation and Optimization of Sn/Gr Lubricants Effects on Cold Extrudability of Fe-TiC Nanocomposite Using Taguchi Robust Design Method
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作者 Seyed Abdolkarim Sajjadi Seyed Mojtaba Zebarjad +2 位作者 Nasrin Sasani Heydar Khadivi Behrooz Naderi 《Engineering(科研)》 2011年第7期700-707,共8页
The present study deals with the effects of both tin (Sn) and graphite (Gr) powders on the cold extrudability of Fe-TiC nanocomposites as lubricant. The production process includes low-energy ball milling, powder meta... The present study deals with the effects of both tin (Sn) and graphite (Gr) powders on the cold extrudability of Fe-TiC nanocomposites as lubricant. The production process includes low-energy ball milling, powder metallurgy and cold direct Extrusion. Due to various factors influencing the extrudability of the Fe-TiC nanocomposites, such as milling time, rate of extrusion, type and content of lubricant and etc, Taguchi robust design method of system optimization was used to determine the approximate contribution percent (% &#961) of each factor. In order to investigation of Fe-TiC properties, samples with best quality of extrusion were analyzed by XRD and SEM investigations. The results indicate that, sitting the atomic layers of Sn lubricant between Fe and TiC particles leads to decreasing the friction. In this case sliding the particles on each other is easier and a part of the load is applied on lubricant. The results of extrusion of samples indicate that using 2% Sn admixed and die wall graphite lubrication can improve cold extrudability of Fe-TiC nanocomposites. 展开更多
关键词 extrudability Fe-TiC LUBRICANT NANOCOMPOSITE Taguchi ROBUST Design Method
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Effects of time-varying liquid bridge forces on rheological properties,and resulting extrudability and constructability of three-dimensional printing mortar 被引量:1
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作者 Peng ZHI Yu-Ching WU Timon RABCZUK 《Frontiers of Structural and Civil Engineering》 SCIE EI CSCD 2023年第9期1295-1309,共15页
Extrudability and constructability are two important,yet contradictory issues pertaining to the construction of three-dimensional(3D)printing concrete.Extrudability is easily achieved when 3D printing cement mortar ha... Extrudability and constructability are two important,yet contradictory issues pertaining to the construction of three-dimensional(3D)printing concrete.Extrudability is easily achieved when 3D printing cement mortar has a high water content and low cohesion,but the printed structure is easily collapsible.However,a 3D printing cement mortar with a low water content and high cohesion has a relatively stable printed structure although the cement mortar might not be extrudable.This study proposes a particle-based method to simulate 3D printing mortar extrusion and construction as an overall planning tool for building design.First,a discrete element model with time-varying liquid bridge forces is developed to investigate the microscopic effects of these forces on global rheological properties.Next,a series of numerical simulations relevant to 3D printable mortar extrudability and constructability are carried out.The study demonstrates that the effects of time-varying liquid bridge forces on rheological properties and the resulting extrudability and constructability of 3D printing mortar are considerable.Furthermore,an optimized region that satisfies both the extrusion and construction requirements is provided for 3D printing industry as a reference. 展开更多
关键词 particle-based simulation liquid bridge force rheological property 3D printing mortar extrudability CONSTRUCTABILITY
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Microstructure and mechanical properties of extruded Mg-Sn alloys with a heterogeneous grain structure 被引量:1
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作者 Lin Tong Jing Jiang +4 位作者 Guangli Bi Yuandong Li Tijun Chen Xiaoru Zhang Daqing Fang 《Journal of Magnesium and Alloys》 2025年第6期2825-2844,共20页
The high-strength Mg-7Sn alloys(wt.%)with a heterogeneous grain structure were prepared by low-temperature extrusion(230°C)with the extrusion ratio of 9:1(9E230)and 17:1(17E230).The two extruded alloys contained ... The high-strength Mg-7Sn alloys(wt.%)with a heterogeneous grain structure were prepared by low-temperature extrusion(230°C)with the extrusion ratio of 9:1(9E230)and 17:1(17E230).The two extruded alloys contained fine dynamic recrystallization(DRX)grains(FG)and coarse un DRX grains(CG).The difference in deformability between CG and FG leads to the formation of heterogeneous grain structure.The average grain size and basal texture intensities increased while the volume fraction of CG decreased with increasing extrusion ratio.Tensile testing results indicated that the extruded 17E230 alloy exhibited higher tensile strengths than 9E230 alloy,whose tensile yield strength(σ_(0.2)),ultimate tensile strengths(σ_(b)),and elongation to failure(ε_(f))were 231.1 MPa,319.5MPa,and 12.54%respectively.The high tensile strengths of the extruded alloy mainly originated from grain refinement,texture strengthening,precipitation strengthening from a great number of nano-scale Mg_(2)Sn phases,solid solution strengthening and hetero-deformation induced(HDI)strengthening,while the good ductility of the alloy was also mainly attributed to grain refinement,activation of the non-basal slip systems and HDI hardening. 展开更多
关键词 Extruded Mg-7Sn alloys HETEROSTRUCTURE Extrusion ratio Microstructure Mechanical properties
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Effects of Co-addition of Ni and Zn on Microstructure and Mechanical Properties of Extruded Mg-Y-Cu Alloy
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作者 Bi Guangli Wei Zhichao +3 位作者 Jiang Jing Zhang Niuming Li Yuandong Chen Tijun 《稀有金属材料与工程》 北大核心 2025年第5期1145-1155,共11页
The effects of the co-addition of Ni and Zn on the microstructure and mechanical properties of the extruded Mg-6.84Y2.45Cu(MYC,wt%)alloy were researched.Results show that the as-cast Mg-6.79Y-1.21Cu-1.12Ni-1.25Zn(MYCN... The effects of the co-addition of Ni and Zn on the microstructure and mechanical properties of the extruded Mg-6.84Y2.45Cu(MYC,wt%)alloy were researched.Results show that the as-cast Mg-6.79Y-1.21Cu-1.12Ni-1.25Zn(MYCNZ,wt%)alloy consists of theα-Mg,a few Y-rich phases,lamellar 18R-long period stacking ordered(LPSO)phase,and granular Mg_(2)(Cu,Ni,Zn)phase.After the homogenization process,phase transformation occurs in MYCNZ alloy.Some 18R-LPSO phases at the grain boundary are transformed into the thin striped 14H-LPSO phase in the grains.After extrusion,the amount,morphology,and distribution of the second phase are changed,and the grain size of the extruded MYCNZ alloy is significantly reduced to approximately 2.62µm.Additionally,a weaker basal texture is formed in the extruded MYCNZ alloy.The tensile results indicate that the co-addition of Ni and Zn significantly enhances the tensile strength of the extruded MYC alloy while maintaining good ductility.The tensile yield strength(σ_(0.2)),ultimate tensile strength(σ_(b)),and elongation to failure(ε_(L))of the extruded MYCNZ alloy are 266.9 MPa,299.8 MPa,and 20.1%,respectively.This alloy has a good strength-plastic synergistic effect.The excellent tensile strength of the extruded MYCNZ alloy at room temperature is mainly due to grain refinement and the second phase strengthening effect,and its outstanding ductility is ascribed to the texture weakening and activation of non-basal slips. 展开更多
关键词 extruded Mg-Y-Cu(Ni Zn)alloy LPSO phase microstructure mechanical properties
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Creep properties and fracture behavior of AZ31B extruded sheets with mixed-grain microstructures of different morphologies
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作者 Xiaoxia Zhang Ming Li +6 位作者 Hongxia Wang Jiao Cui Lei Song Naidong Ren Lifei Wang Weili Cheng Kwangseon Shin 《Journal of Magnesium and Alloys》 2025年第2期777-791,共15页
In this work,AZ31B extruded sheets with mixed-grain microstructures were prepared through extrusion.Samples of mixed-grain microstructure with different morphologies were selected from the AZ31B extruded sheets(referr... In this work,AZ31B extruded sheets with mixed-grain microstructures were prepared through extrusion.Samples of mixed-grain microstructure with different morphologies were selected from the AZ31B extruded sheets(referred to as M1 and M2 samples,respectively).The creep tests were performed on these samples at the temperature range of 150-200℃,and the stress level range of 50-100 MPa.The creep properties and fracture behavior of AZ31 extruded sheets with mixed-grain microstructures were studied.Results showed that the creep properties of the M2 sample always outperformed that of the M1 sample and M1 and M2 samples’creep was dominated by dislocation movement.The creep rate of M2 samples(1.5×10^(-7)±1.1×10^(-10) s^(-1))is an order of magnitude lower than that of M1 samples(4.8×10^(-6)±8.1×10^(-10) s^(-1))at 200℃under 50 MPa The high activity of basal slip and softening mechanism in the M1 sample significantly accelerated creep,resulting in a relatively high creep rate.Moreover,the stress concentration within the M1 sample caused by deformation incompatibility,increased the initiation and propagation of voids,ultimately leading to fracture and poorer creep performance.However,the numerous<10µm fine grains surrounding deformed coarse grains in the M2 sample facilitated better coordination of deformation through dislocation slip,effectively slowing down the initiation of voids during the creep process.Meanwhile,the strain was uniformly distributed within each grain,mitigating stress concentration,inhibiting voids propagation,and contributing to the superior creep resistance of the M2 sample. 展开更多
关键词 AZ31B extruded sheets Mixed-grain microstructure Creep properties Fracture behavior
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Numerical Simulations of Polymer Melt Conveying in Co-Rotating Twin Screw Extruder 被引量:7
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作者 彭炯 陈晋南 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期189-192,共4页
The 3 D non isothermal flow of non Newtonian viscous polymer melt in a co rotating twin screw extruder is modeled. The distributions of the velocity, temperature, pressure and the viscous dissipation in the fl... The 3 D non isothermal flow of non Newtonian viscous polymer melt in a co rotating twin screw extruder is modeled. The distributions of the velocity, temperature, pressure and the viscous dissipation in the flow domain are presented by using a fluid dynamics analysis package (Polyflow). The numerical results show that the temperatures are high in the intermeshing region and on the screw surface, the maximum pressure and the minimum pressure occur in the intermeshing region, and the flow rate is almost proportional to the screw speed. 展开更多
关键词 twin screw extruder non Newtonian fluid numerical simulation
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Extrusion limit diagram of AZ91–0.9Ca–0.6Y–0.5MM alloy and effects of extrusion parameters on its microstructure and mechanical properties 被引量:1
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作者 Dong HeeLee Ye Jin Kim +2 位作者 Sang-Hoon Kim Byoung Gi Moon Sung Hyuk Park 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第12期3447-3458,共12页
An AZ91–0.9Ca–0.6Y–0.5MM(AZXWMM91100) alloy, which has higher corrosion resistance, ignition resistance, and extrudability than a commercial AZ91 alloy, has been developed recently. In this study, the AZXWMM91100 a... An AZ91–0.9Ca–0.6Y–0.5MM(AZXWMM91100) alloy, which has higher corrosion resistance, ignition resistance, and extrudability than a commercial AZ91 alloy, has been developed recently. In this study, the AZXWMM91100 alloy is extruded at various temperatures(300–400 ℃) and ram speeds(1–14.5 mm/s), and the cracking behaviors, microstructure, and tensile properties of the extruded materials are systematically analyzed. On the basis of the pressure limit and surface and internal cracking limit, the extrusion limit diagram providing a safe extrusion processing zone is established. All of the materials extruded at temperatures and speeds within the safe extrusion processing zone have high surface quality and moderate tensile ductility with an elongation higher than 10%. Moreover, they have a fully recrystallized grain structure and contain undissolved particle stringers arranged parallel to the extrusion direction. The grain size of the extruded material does not show any relationship with the Zener–Hollomon parameter(Z). However, the yield strength(YS) of the extruded material is inversely proportional to the logarithm of the Z value, and their relationship is expressed as YS =-31.2·log(Z) + 536. These findings may broaden the understanding of the AZXWMM91100 alloy with excellent chemical and physical properties and provide valuable information for the development of high-performance extruded Mg products using this alloy. 展开更多
关键词 MAGNESIUM extrudability Extrusion limit diagram Microstructure Tensile properties
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Chemical and mechanical properties of stainless, environment-friendly, and nonflammable Mg alloys (SEN alloys): A review
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作者 Jong Un Lee Hyun Ji Kim +5 位作者 Sang-Cheol Jin Ye Jin Kim Young Min Kim Bong Sun You Jun Ho Bae Sung Hyuk Park 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期841-872,共32页
This review article provides overall understanding of stainless,environment-friendly,and nonflammable Mg alloys(SEN alloys)recently developed at the Korea Institute of Materials Science.SEN alloys are produced by addi... This review article provides overall understanding of stainless,environment-friendly,and nonflammable Mg alloys(SEN alloys)recently developed at the Korea Institute of Materials Science.SEN alloys are produced by adding small amounts of Ca and Y(each<1 wt%)into commercial Mg–Al based alloys,resulting in exceptional ignition and corrosion resistances and impressive mechanical properties.Their main advantages of SEN alloys are as follows.(1)A dense multi-oxide layer of SEN alloys comprising MgO,CaO,and Y_(2)O_(3) impedes the outward dispersion of Mg vapor and the inward penetration of O_(2) during oxidation,thereby enhancing the oxidation and ignition resistances.(2)The presence of Ca-and Y-based second-phase particles in SEN alloys can enhance their corrosion resistance because Ca-containing particles prevent the spread of corrosion,and the replacement of Al-containing particles with less noble ones containing Y(e.g.,Al–Mn–Y or Al–Y particles)retards corrosion.(3)The addition of minor amounts of Ca and Y renders excellent mechanical properties due to improved strengthening effects.These enhanced properties are attributed to more pronounced dynamic recrystallization and grain refining behaviors caused by the second-phase particles during extrusion.(4)Despite the presence of various types of second-phase particles,the fatigue properties of SEN9 alloys are similar to those of commercial AZ91 alloys.(5)Simultaneous introduction of Ca and Y suppresses the formation of Mg17Al12 discontinuous precipitates during aging,leading to the enhanced elongation of aged SEN alloys.(6)Adding mischmetal into the SEN9 alloy leads to a six-fold enhancement in extrudability.Consequently,the studies conducted on SEN alloys demonstrate their excellent ignition and corrosion resistances and mechanical properties,which broaden the industrial applications of Mg alloys by addressing their inherent weaknesses. 展开更多
关键词 SEN magnesium alloy Corrosion resistance Ignition resistance Mechanical properties extrudability.
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在VISUAL LISP环境下圆柱状螺旋弹簧建模的实现
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作者 齐颖 张晔 《通化师范学院学报》 2006年第2期37-38,共2页
在AUTOCAD的实际应用中,使用常用工具圆柱状螺旋弹簧的建模很难实现,甚至根本无法完成.为了解决这个问题,本文通过编制VISUAL LISP程序来实现.这样,在AUTOCAD环境下该程序不仅可以完成圆柱状螺旋线自动绘图,简化建模的过程,也可以完成... 在AUTOCAD的实际应用中,使用常用工具圆柱状螺旋弹簧的建模很难实现,甚至根本无法完成.为了解决这个问题,本文通过编制VISUAL LISP程序来实现.这样,在AUTOCAD环境下该程序不仅可以完成圆柱状螺旋线自动绘图,简化建模的过程,也可以完成使用常用工具建模所不能实现的模型. 展开更多
关键词 VISUAL LISP平台 螺旋线基点 三雏 路径 EXTRUDE SLICE
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Study of glue extrusion after endoscopic N-butyl-2-cyanoacrylate injection on gastric variceal bleeding 被引量:14
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作者 Yan-Mei Wang Liu-Fang Cheng Nan Li Kai Wu Jun-Shan Zhai Ya-Wen Wang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第39期4945-4951,共7页
AIM:To investigate glue extrusion after endoscopic N-butyl-2-cyanoacrylate injection on gastric variceal bleeding and to evaluate the long-term efficacy and safety of this therapy.METHODS:A total of 148 cirrhotic pati... AIM:To investigate glue extrusion after endoscopic N-butyl-2-cyanoacrylate injection on gastric variceal bleeding and to evaluate the long-term efficacy and safety of this therapy.METHODS:A total of 148 cirrhotic patients in our hospital with esophagogastric variceal bleeding(EGVB) were included in this study.N-butyl-2-cyanoacrylate was mixed with lipiodol in a 1:1 ratio and injected as a bolus of 1-3 mL according to variceal size.Patients underwent endoscopic follow-up the next week,fourth week,second month,fourth month,and seventh month after injection and then every 6 mo to determine the cast shape.An abdominal X-ray fi lm and ultrasound or computed tomographic scan were also carried out in order to evaluate the time of variceal disappearance and complete extrusion of the cast.The average follow-up time was 13.1 mo.RESULTS:The instantaneous hemostatic rate was 96.2%.Early re-bleeding after injection in 9 cases(6.2%) was estimated from rejection of adhesive.Late re-bleeding occurred in 12 patients(8.1%) at 2-18 mo.The glue cast was extruded into the lumen within one month in 86.1% of patients and eliminated within one year.Light erosion was seen at the injection position and mucosa edema in the second week.The glue casts were extruded in 18 patients(12.1%) after one week and in 64 patients(42.8%) after two weeks.All kinds of glue clumping shapes and colors on endoscopic examination were observed in 127 patients(86.1%) within one month,including punctiform,globular,pillar and variform.Forty one patients(27.9%) had glue extrusion after 3 mo and 28 patients(28.9%) after six months.The extrusion time was not related to the injection volume of histoacryl.Obliteration was seen in 70.2%(104 cases) endoscopically.The main complication was re-bleeding resulting from extrusion.The prognosis of the patients depended on the severity of the underlying liver disease.CONCLUSION:Endoscopic injection of cyanoacrylate is highly effective for gastric varices bleeding.The glue clump shape is correlated with anatomic structure of vessels.The time of extrusion was not related to dosage of the glue. 展开更多
关键词 Gastric variceal bleeding Glue extruded N-butyl-2-cyanoacrylate Portal hypertension
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Microstructure and yield phenomenon of an extruded Mg-Y-Cu alloy with LPSO phase 被引量:20
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作者 Guangli Bi Niuming Zhang +6 位作者 Jing Jiang Yuandong Li Tijun Chen Wei Fu Xiaoru Zhang Daqing Fang Xiangdong Ding 《Journal of Rare Earths》 SCIE EI CAS CSCD 2023年第3期454-461,I0005,共9页
A yield phenomenon was firstly reported in an extruded Mg-6.8Y-2.5Cu alloy and the corresponding microstructure was also investigated in this work,The cast alloy is mainly composed ofα-Mg,18R long period stacking ord... A yield phenomenon was firstly reported in an extruded Mg-6.8Y-2.5Cu alloy and the corresponding microstructure was also investigated in this work,The cast alloy is mainly composed ofα-Mg,18R long period stacking order(LPSO)phase,eutectic phase(Mg_(20)Cu_(4)Y_(1)),and Mg_(2)Cu phase.The 18R LPSO phase at the dendritic grain boundary transforms into the 14H LPSO phase in the grain interior during homogenization.After extrusion,the grain size of the homogenized alloy is remarkably refined to-3.69μm and the second phase is significantly broken and distributed in the extrusion direction.Tensile testing curves of the extrude alloy at room temperature indicate that the yield strength and ultimate tensile strength increase while the elongation of the alloy decreases with increasing strain rate.Interestingly,a yield plateau fo rms and gradually decreases with increasing strain rate.The yield phenomenon is related to the dislocation multiplication and the interaction between the movable dislocations and solute atoms. 展开更多
关键词 Extruded Mg-6.8Y-2.5Cu alloy Long period stacking order phase MICROSTRUCTURE Yield phenomenon Rare earths
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Effects of single and multi-stage solid solution treatments on microstructure and properties of as-extruded AA7055 helical profile 被引量:13
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作者 Cun-sheng ZHANG Zhao-gang ZHANG +3 位作者 Ming-fu LIU En-cheng BAO Liang CHEN Guo-qun ZHAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第7期1885-1901,共17页
The effects of single-stage solution treatment(SST),enhanced solution treatment(EST),high-temperature pre-precipitation(HTPP)and multi-stage solution treatment(MST)on the microstructure,mechanical properties and corro... The effects of single-stage solution treatment(SST),enhanced solution treatment(EST),high-temperature pre-precipitation(HTPP)and multi-stage solution treatment(MST)on the microstructure,mechanical properties and corrosion resistance of the as-extruded 7055 aluminium alloy(AA7055)helical profile were investigated using differential scanning calorimetry(DSC),optical microscopy(OM),scanning electron microscopy(SEM),electron back-scattered diffraction(EBSD)and transmission electron microscopy(TEM).It was observed that EST and MST could promote the dissolution of the second-phase particles compared with the traditional SST,and the intergranular phases were distinctly discontinuously distributed after HTPP and MST.There was obvious difference in the main texture type and texture strength for the alloy after different solid solution treatments.HTPP could improve the corrosion resistance of the alloy by regulating the intergranular phases,but the mechanical properties were severely weakened.While the good corrosion resistance of the alloy could be obtained by MST without obvious strength loss.As a result,the MST is an ideal solid solution treatment scheme for AA7055. 展开更多
关键词 7055 aluminum alloy extruded profile solid solution treatment mechanical properties corrosion resistance
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Methane aromatization in the absence of oxygen over extruded and molded MoO_3/ZSM-5 catalysts:Influences of binder and molding method 被引量:8
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作者 Dongmei Ren Xiangsheng Wang +3 位作者 Gang Li Xiaojing Cheng Huayun Long Lidong Chen 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2010年第6期646-652,共7页
The influences of binder and molding method on the catalytic performance of methane aromatization in the absence of O2 over MoO3/ZSM-5 catalysts were investigated.SEM,NH3-TPD,FT-IR of adsorbed pyridine,N2 adsorption-d... The influences of binder and molding method on the catalytic performance of methane aromatization in the absence of O2 over MoO3/ZSM-5 catalysts were investigated.SEM,NH3-TPD,FT-IR of adsorbed pyridine,N2 adsorption-desorption,cyclohexane adsorption and XPS were employed to characterize the physical and chemical properties of the catalysts.It was found that SiO2 was a suitable binder for the catalyst due to its appropriate weak acidity.The laminar catalyst comprising of an inert spherical core and a MoO3/ZSM-5 laminar shell with 0.1 0.2 mm in thickness showed a better catalytic performance than the extruded catalyst.The improved activity of the laminar catalyst could be attributed to the easy carbonization of Mo species and the quick removal of reaction products from the catalyst surface. 展开更多
关键词 methane AROMATIZATION extruded catalyst laminar catalyst ZSM-5 molybdenum
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Dynamic compressive property and failure behavior of extruded Mg-Gd-Y alloy under high temperatures and high strain rates 被引量:10
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作者 Jin-cheng Yu Zheng Liu +1 位作者 Yang Dong Zhi Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS 2015年第2期134-141,共8页
For the purpose of investigating the dynamic deformational behavior and failure mechanisms of magnesium under high strain rates,the Split Hopkinson Pressure Bar(SHPB)was used for investigating dynamic mechanical prope... For the purpose of investigating the dynamic deformational behavior and failure mechanisms of magnesium under high strain rates,the Split Hopkinson Pressure Bar(SHPB)was used for investigating dynamic mechanical properties of extruded Mg-Gd-Y Magnesium alloy at ambient temperature(300 K),200℃(473 K)and 300℃(573 K)temperature.The samples after compression were analyzed by scanning electron microscope(SEM)and metallographic microscope.Dynamic mechanical properties,crack performance and plastic deformation mechanism of extruded Mg-Gd-Y Magnesium alloy along the extrusion direction(ED)were discussed.The results show that,extruded Mg-Gd-Y Magnesium alloy has the largest dynamic compressive strength which is 535 MPa at ambient temperature(300 K)and strain rate of 2826 s^(−1).When temperature increases,dynamic compressive strength decreases,while ductility increases.The dynamic compression fracture mechanism of extruded Mg-Gd-Y Magnesium alloy is multi-crack propagation and intergranular quasi-cleavage fracture at both ambient temperature and high temperature.The dynamic compressive deformation mechanism of extruded Mg-Gd-Y Magnesium alloy is a combination of twinning,slipping and dynamic recrystallization at both ambient temperature and high temperature. 展开更多
关键词 Extruded Mg-Gd-Y magnesium alloy Split Hopkinson Pressure Bar Dynamic compressive property Failure behavior High strain rates High temperature
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A comparison study of Ce/La and Ca microalloying on the bio-corrosion behaviors of extruded Mg-Zn alloys 被引量:11
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作者 J.H.Chu L.B.Tong +4 位作者 Z.H.Jiang D.N.Zou Q.J.Wang S.F.Liu H.J.Zhang 《Journal of Magnesium and Alloys》 SCIE EI CAS 2020年第4期1269-1280,共12页
The influences of Ca and Ce/La microalloying on the microstructure evolution and bio-corrosion resistances of extruded Mg-Zn alloys have been systematically investigated in the current study.Compared with single Ca or... The influences of Ca and Ce/La microalloying on the microstructure evolution and bio-corrosion resistances of extruded Mg-Zn alloys have been systematically investigated in the current study.Compared with single Ca or Ce/La addition,the Ca-Ce/La cooperative microalloying results in an outstanding grain refinement,because the fine secondary phase particles effectively hinder the recrystallized grain growth.The coarse Ca2Mg6Zn3 phases promote the formation of Ca3(PO4)2 or hydroxyapatite particles during the immersion process and accelerate the dissolution of the corrosion product film,which destroys its integrity and results in the deterioration of anti-corrosive performance.The Ce/La elements can be dispersed within the conventional Mg7Zn3 phases,which reduce the internal galvanic corrosion between Mg matrix and the secondary phases,leading to an obvious improvement of corrosion resistance.Therefore,the Ca-Ce/La cooperative microalloying achieves a homogenous fine-grained microstructure and improves the protective ability of surface film,which will pave a new avenue for the design of biomedical Mg alloys in the coming future. 展开更多
关键词 Extruded Mg-Zn alloy Ca and Ce/La microalloying Microstructure evolution Bio-corrosion behaviors
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Effect of Replacing Fish Meal with Extruded Soybean Meal on Growth, Feed Utilization and Apparent Nutrient Digestibility of Juvenile White Shrimp(Litopenaeus vannamei) 被引量:5
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作者 YANG Qihui TAN Beiping +2 位作者 DONG Xiaohui CHI Shuyan LIU Hongyu 《Journal of Ocean University of China》 SCIE CAS 2015年第5期865-872,共8页
Extruded soybean meal (ESBM) was evaluated as a protein source for partial replacement of fish meal (FM) in diets of juvenile Litopenaeus vannarnei. In the control diet (Diet 1), FM protein was replaced with inc... Extruded soybean meal (ESBM) was evaluated as a protein source for partial replacement of fish meal (FM) in diets of juvenile Litopenaeus vannarnei. In the control diet (Diet 1), FM protein was replaced with increasing dietary levels of ESBM (4.28%, 8.40%, 12.62%, 16.82%, and 25.26%) at 10%, 20%, 30%, 40%, and 60% levels (Diets 2 to 6, respectively). An eight-week feeding trial was conducted on 720 juvenile shrimp (0.67 g ± 0.01 g mean initial Weight), and nutrient digestibility of the six diets was determined. ESBM could replace 20% of FM without causing a significant reduction in growth of shrimp, but other dietary treatments strongly affected whole body composition. Crude protein content of the whole body fed Diet 6 was significantly lower than that fed Diet 2 (P〈0.05), while crude lipid content of the whole body fed Diet 5 or 6 was significantly higher than that fed Diet 2 (P〈0,05). Protein digestibilities of Diets 5 and 6 were significantly lower than that of Diet 1 (P〈0.05). Digestibility of lipids ranged from 96.97% in Diet 6 to 98.34% in Diet 3, whereas dry matter digestibility decreased with increasing replacement level. This study indicates that 20% FM replacement with ESBM in the basic diet containing 40% protein and 30% FM is optimal for juvenile L. vannamei. 展开更多
关键词 Litopenaeus vannamei fish meal extruded soybean meal growth performance feed ttilization nutrient digestibility
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Low cycle fatigue behavior of the extruded AZ80 magnesium alloy under different strain amplitudes and strain rates 被引量:7
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作者 Cong Wang Tianjiao Luo Yuansheng Yang 《Journal of Magnesium and Alloys》 SCIE EI CAS 2016年第3期181-187,共7页
Low cycle fatigue behavior of extruded AZ80 magnesium alloy was investigated under uniaxial tension-compression at different strain amplitudes and strain rates.The results show that the extruded AZ80 magnesium alloy e... Low cycle fatigue behavior of extruded AZ80 magnesium alloy was investigated under uniaxial tension-compression at different strain amplitudes and strain rates.The results show that the extruded AZ80 magnesium alloy exhibits cyclic hardening at strain amplitudes ranging from 0.4%to 1.0%,the asymmetry of hysteresis loops becomes increasingly obvious when the strain amplitude increases.Higher strain rates correspond to higher stress amplitudes,high mean stresses and short fatigue life.{10–12}extension twins play a role in the cyclic deformation under higher strain amplitudes(0.8%,1.0%).The relationship between total strain energy density and fatigue life can be described by the modified Morrow model.The effect of strain rate on the fatigue life can also be predicted by the model. 展开更多
关键词 Low cycle fatigue Magnesium alloy Extruded AZ80 Strain amplitude Strain rate
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Effects of Y content and temperature on the damping capacity of extruded Mg-Y sheets 被引量:10
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作者 Y.T.Tang C.Zhang +5 位作者 L.B.Ren W.Yang D.D.Yin G.H.Huang H.Zhou Y.B.Zhang 《Journal of Magnesium and Alloys》 SCIE 2019年第3期522-528,共7页
The damping behavior of extruded Mg-xY(x=0.5,1.0,3.0 wt.%)sheets were investigated in detail concerning the effects of Y addition and temperature,and the relationship between damping capacity and yield strength was di... The damping behavior of extruded Mg-xY(x=0.5,1.0,3.0 wt.%)sheets were investigated in detail concerning the effects of Y addition and temperature,and the relationship between damping capacity and yield strength was discussed.At room temperature(RT),with Y content increasing from 0.5%to 3.0%,the damping capacity(Q-1)significantly decreased from 0.037 to 0.015.For all the studied sheets,the relationship between strain amplitude and Q-1 fitted well with the Granato and Liicke(G-L)dislocation damping model.With temperature increased,the G-L plots deviated from linearity indicating that the dislocation damping was not the only dominate mechanism,and the grain boundary sliding(GBS)could contribute to damping capacity.Consequently,the Q-1 increased remarkably above the critical temperature,and the critical temperature increased significantly from 50℃ to 290℃ with increasing Y contents from 0 to 3.0wt.%.This result implied that the segregation of Y solutes at grain boundary could depress the GBS,which was consistent with the recent finding of segregation tendency for rare-earth solutes.The extruded Mg-IY sheet exhibited slightly higher yield strength(Rp0.2)and Q-1 comparing with high-damping Mg-0.6Zr at RT.At an elevated temperature of 325℃,the Mg-IY sheet had similar Q-1 but over 3 times larger Rp0.2 than that of the pure Mg.The present study indicated that the extruded Mg-Y based alloys exhibited promising potential for developing high-performance damping alloys,especially for the elevated-temperature application. 展开更多
关键词 Extruded sheets Mg-Y alloys Damping capacity Granato and Lücke model Elevated temperature
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Texture evaluation in warm deformation of an extruded Mg-6Al-3Zn alloy 被引量:5
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作者 M.Kavyani G.R.Ebrahimi +1 位作者 M.Sanjari M.Haghshenas 《Journal of Magnesium and Alloys》 SCIE EI CAS 2016年第2期89-98,共10页
To assess the effect of strain and strain rate on texture evolution of an extruded Mg–6Al–3Zn alloy,compression tests were carried out.Samples were prepared in the extrusion direction(ED)and normal direction(ND).The... To assess the effect of strain and strain rate on texture evolution of an extruded Mg–6Al–3Zn alloy,compression tests were carried out.Samples were prepared in the extrusion direction(ED)and normal direction(ND).The compression tests were performed at 250℃ and with different strain rates of 0.01 sec−1 and 1 sec−1 and different strains.Microstructural observation and texture investigation show that at early stages of deformation,extension twins lead to the development of strong basal texture intensity along rolling direction(RD)in ED samples and contraction twins result in texture evolution along transverse direction(TD)in ND samples.Also,microstructural investigation at high strains reveals that dynamic recrystallization occurs in both samples and consequently the basal texture intensity has been decreased. 展开更多
关键词 Extruded magnesium alloy Deformation texture TWINNING RECRYSTALLIZATION
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