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1Late Quaternary sinistral slip rate along the Altyn Tagh fault and its structural transformation model显示文摘Based on technical processing of high-resolution SPOT images and aerophotos, detailed mapping of offset landforms in combination with field examination and displacement measurement, and dating of offset geomorphic surfaces by using carbon fourteen (14C), cos- mogenic nuclides (10Be+26Al) and thermoluminescence (TL) methods, the Holocene sinistral slip rates on different segments of the Altyn Tagh Fault (ATF) are obtained. The slip rates reach 17.5 ±2 mm/a on the central and western segments west of Aksay Town, 11±3.5 mm/a on the Subei-Shibaocheng segment, 4.8±1.0 mm/a on the Sulehe segment and only 2.2±0.2 mm/a on the Kuantanshan segment, an easternmost segment of the ATF. The sudden change points for loss of sinistral slip rates are located at the Subei, Shibaocheng and Shulehe triple junctions where NW-trending active thrust faults splay from the ATF and propagate southeastward. Slip vector analyses indicate that the loss of the sinistral slip rates from west to east across a triple junction has structurally transformed into local crustal shortening perpendicular to the active thrust faults and strong uplifting of the thrust sheets to form the NW-trending Danghe Nanshan, Daxueshan and Qilianshan Ranges. Therefore, the eastward extrusion of the northern Qing- hai-Tibetan Plateau is limited and this is in accord with “the imbricated thrusting transforma- tion-limited extrusion model”.P. Tapponnier J. Van Der Woerd F. J. Ryerson A.S. Meriaux 2005Science China Earth Sciences2005,48,3:32
23D bioprinting for biomedical devices and tissue engineering: A review of recent trends and advances显示文摘3D printing,an additive manufacturing based technology for precise 3D construction,is currently widely employed to enhance applicability and function of cell laden scaffolds.Research on novel compatible biomaterials for bioprinting exhibiting fast crosslinking properties is an essential prerequisite toward advancing 3D printing applications in tissue engineering.Printability to improve fabrication process and cell encapsulation are two of the main factors to be considered in development of 3D bioprinting.Other important factors include but are not limited to printing fidelity,stability,crosslinking time,biocompatibility,cell encapsulation and proliferation,shear-thinning properties,and mechanical properties such as mechanical strength and elasticity.In this review,we recite recent promising advances in bioink development as well as bioprinting methods.Also,an effort has been made to include studies with diverse types of crosslinking methods such as photo,chemical and ultraviolet(UV).We also propose the challenges and future outlook of 3D bioprinting application in medical sciences and discuss the high performance bioinks.Soroosh Derakhshanfar Rene Mbeleck Kaige Xu Xingying Zhang Wen Zhong Malcolm Xing 2018Bioactive Materials2018,3,2:21
3Mechanical properties of Mg-8Gd-3Y-0.5Zr alloy with bimodal grain size distributions显示文摘The Mg-Gd-Y-Zn-Zr alloys are representational and potential age-hardening systems as reported in the past ten years,but their mechanical properties are still dependent on the grain size and its distribution.The effect of bimodal structure on mechanical properties of Mg-8Gd-3Y-0.5Zr alloy with bimodal grain size distributions was investigated.The results suggested that the volume fraction of fine grain(FG)and coarse grain(CG)could be controlled by combined processes of hot forging,extrusion and annealing.And for the present alloys with bimodal grain size distribution,the improvement of strength is still attributed to the grain refinement.The morphology of bimodal grain size distribution has a marked impact on the ductility of the alloy,i.e.with the increase of coarse grain volume fraction,the elongation to failure increases at the beginning and then decreases.The mechanism of the toughening effect of bimodal grain size distribution on the Mg-Gd-Y-Zn-Zr alloys with bimodal grain size structure has been discussed.J.H.He L.Jin F.H.Wang S.Dong J.Dong 2017Journal of Magnesium and Alloys2017,5,4:15
4Effect of Nd on microstructure and mechanical properties of as-extruded Mg-Y-Zr-Nd alloy显示文摘The microstructure and mechanical properties of Mg-Y-Zr-x Nd alloys with 0–2.63 wt% Nd were investigated using optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and tensile testing test. Results indicated that more Mg_(24)Y_5 particles and Mg_(14)Nd_2Y(β) phases were dispersed in the matrix when Nd content increased from 0 wt% to 2.63 wt% in the extruded alloys.Consequently, the nucleation of dynamic recrystallization and the volume fraction of recrystallized grains were promoted obviously. The average grain size can be refined in the range of 4.6–1.3 μm after the addition of 2.63 wt% Nd. The tensile strength of extruded alloys increased with increasing Nd content, and elongation exhibited an opposite change tendency. The extruded alloy sheet with 1.01 wt% Nd demonstrates optimal combination of strength and plasticity, i.e., the ultimate tensile strength, yield strength,and elongation were 273 MPa, 214 MPa, and 24.2%, respectively. Variations in mechanical properties are discussed on the basis of microstructure observations.Xiaoyang Xu Xianhua Chen Weiwei Du Yuxiao Geng Fusheng Pan 2017Journal of Materials Science & Technology2017,33,9:14
5Review on the effect of different processing techniques on the microstructure and mechanical behaviour of AZ31 Magnesium alloy显示文摘Magnesium(Mg)alloys despite being the ideal candidate for structural applications,owing to their high specific strength and low density,are not widely used due to lack of active slip systems at room temperature in their hexagonal close-packed crystal structure,eliciting poor ductility and formability.Amongst the various series of Mg alloys,the AZ and ZK series alloys have been standouts,as they inherit better room temperature strength and flow characteristics through their solute elements.Grain refinement,as well as eliminating casting defects through metal processing techniques are vital for the commercial viability of these alloys since they play a key role in controlling the mechanical behaviour.As such,this review highlights the effect of different Bulk-deformation and Severe Plastic Deformation techniques on the crystal orientation and the corresponding mechanical behaviours of the AZ31 alloy.However,every process parameter surrounding these techniques must be well thought of,as they require specially designed tools.With the advent of finite element analysis,these processes could be computationally realized for different parameters and optimized in an economically viable manner.Hence,this article also covers the developments made in finite element methods towards these techniques.Rakshith M. Seenuvasaperumal P. 2021Journal of Magnesium and Alloys2021,9,5:12
6The western boundary of extrusion blocks in the southeastern Tibetan Plateau显示文摘The model about block extrusion related to collision between Eurasia and India which is proposed by Tapponnier et al. has not been accepted so far in the field. Based on kinematics and chronology, the Gailigong dextral strike-slip fault in west Yunnan and Nabang dextral strike-slip fault which is the part of Mogok belt are the western boundary of extrusion blocks, as the eastern boundary Red River-Ailaoshan left-lateral fault. And more studies show that as the important way for absorbing the convergence between two continents, the age of blocks’ multistage extrusion is about 23 and 13 Ma.JI Jianqing ZHONG Dalai SANG Haiqing ZHANG Liansheng 2000Chinese Science Bulletin2000,45,10:11
7Effect of Y addition on microstructure and corrosion behavior of extruded Mg-Zn-Nd-Zr alloy显示文摘In this study,the effect of Y addition(0,0.5,1 and 2 wt%)on microstructure and corrosion properties of Mg-6Zn-0.5Zr-1 Nd(wt%)alloy was investigated.The alloys were produced by low-pressure die casting method and extruded at 300℃and 400℃after homogenization treatment at 400℃for 24 h.The results showed that the as-cast microstructure of the alloy with no Y addition consisted ofα-Mg,Mg-Zn binary and Mg-Zn-Nd ternary phases.With increasing Y additions,the average grain size showed a substantial decrease and two kinds of ternary Mg-Zn-Y ternary phases,designated as I-phase(Mg3Zn6Y)and W-phase(Mg3Zn3Y2)were formed.Homogenization treatment resulted in a partial dissolution of second phase particles.Extrusion process gave rise to a remarkable grain refinement due to the DRX mechanism.The extruded alloys with no Y addition exhibited poor corrosion resistance due to the strong micro galvanic coupling effect.Y additions up to 1 wt%improved the corrosion resistance due to the formation of finer grains,fine and uniform distribution of second phase particles and more stable oxide film.Huseyin Zengin Yunus Turen 2020Journal of Magnesium and Alloys2020,8,3:11
8Influence of different extrusion processes on mechanical properties of magnesium alloy显示文摘AZ31 Mg alloy sheets were processed by the conventional symmetrical extrusion(CSE)and the asymmetric extrusion(ASE).Progressive-asymmetric extrusion(PASE)and severe strain-asymmetric extrusion(SASE)were employed for ASE processes.The texture at near-surface and mid-layer zones of ASE sheets was diverse penetrating the normal direction(ND).This was attributed to an additional asymmetric shear strain deformation during the ASE process.(0002)basal planes of PASE sheets tilt to the shear deformation direction.Meanwhile,the basal texture intensity of PASE sheets has been weakened compared with one in CSE sheets.Grain refinement and tilted weak basal texture obtained by SASE process dramatically enhances the room temperature strength and plasticity of the extruded AZ31 magnesium alloy sheets.The microstructure and mechanical responses were examined and discussed.Qingshan Yang Bin Jiang Hucheng Pan Bo Song Zhongtao Jiang Jiahong Dai Lifei Wang Fusheng Pan 2014Journal of Magnesium and Alloys2014,2,3:11
9Microstructure and mechanical properties of A356 alloy with yttrium addition processed by hot extrusion显示文摘The effects of the rare earth element yttrium(Y) and hot extrusion on the microstructure and mechanical properties of A356 alloy were investigated by mechanical properties testing and microstructure observation. The results indicate that the addition of Y improves the microstructure of the as-cast alloy. The distribution of primary α-Al is uniform and orderly. The long needle-like eutectic Si phases and β-Fe phases turn to strips and short rods. When the content of Y increases to 0.2 wt%, the mean diameter of aAl(40.3 μm) and the aspect ratio of the eutectic Si phase(2.3) reach the minimum values, which are68.9% and 86.1% lower, respectively, than that of the alloy without Y addition. Under extrusion stress, the shape of the eutectic Si phase is changed from long rod-like to near grain-like after solution treatment.The size of the eutectic Si phase is significantly reduced. The needle-like β-Fe phases are squeezed and broken. The mechanical properties of the as-extruded alloy are significantly improved compared to the as-cast alloy. When the rare earth content is 0.2 wt%, the ultimate tensile strength, hardness and elongation of the alloy reach the maximum values, which are 328.2 MPa, 110.4 HV and 21.3%, respectively, and increase by 42.01%, 37.71% and 481.91%, respectively, in comparison to the as-cast alloy without Y addition.Zhifan Wei Yushun Lei Hong Yan Xihao Xu Jiajia He 2019Journal of Rare Earths2019,37,6:11
10Corrosion behavior of Mg-Mn-Ca alloy:Influences of Al,Sn and Zn显示文摘The effects of different elements including Al,Sn and Zn with ability of solution hardening on corrosion behavior of a Mg alloy have been studied.The microstructure was analyzed and the electrochemical and immersion techniques were used for corrosion studies.Scanning kelvin probe force microscopy(SKPFM)was utilized to analyze the volta-potential distribution on the surface.It was found that all additives reduced the corrosion resistance;however,Zn decreased the corrosion resistance less than Al and Sn.The corrosion rate was quantitatively explained through volta-potential difference and the second phase fraction.Ahmad Bahmani Srinivasan Arthanari Kwang Seon Shin 2019Journal of Magnesium and Alloys2019,7,1:10
11Microstructure evolution of processed Mg-Al-Zn alloy by equal channel angular extrusion in semi-solid isothermal treatment姜巨福 罗守靖 2006Transactions of Nonferrous Metals Society of China2006,7,6:9
12Microstructures and tensile properties of Mg-Zn-(Gd)-Zr alloys extruded at various temperatures显示文摘The microstructures and tensile properties of Mg-6.0 Zn-0.6 Zr(ZK60) and ZK60 + 1.8 Gd(ZEK620(RE = Gd)) alloys extruded at 290, 305, 320, 340 and360 ℃ were investigated. The results indicate that Gd addition can refine the microstructures of ZK60 alloy and the extrusion parameters such as the extrusion temperature will influence the tensile properties of both as-extruded ZK60 and ZEK620 alloys, although it is much slighter for ZK60 alloy. And the sensitivity is closely related to the textures developed during extrusion. In addition, Gd addition will also clearly improve the tensile strength at room temperature(24 ℃) and particularly at high temperatures(150 and 200 ℃), due to the much finer grains and smaller intermetallic particles. The highest strength is achieved in the as-extruded ZEK620 alloy with extrusion temperature of 320 ℃, with ultimate tensile strength(UTS) and tensile yield strength(TYS) of 405 and375 MPa, respectively, which are improved by approximately 9% and 11% than those of the as-extruded ZK60 alloy which owns the highest strength at extrusion temperature of 290 ℃.Xin Qiu Qiang Yang Kai Guan Fanqiang Bu Zhan-Yi Cao Yong-Bing Liu Jian Meng 2017Rare Metals2017,36,12:9
13Application of computer-aided engineering optimum design method in aluminum profile extrusion mould显示文摘The finite element analysis and the optimum design of aluminum profile extrusion mould were investigated using the ANSYS software and its parameterized modeling method. The optimum dimensions of the mould were obtained. It is found that the stress distribution is very uneven, and the stress convergence is rather severe in the bridge of the aluminum profile extrusion mould. The optimum height of the mould is 70.527 mm, and the optimum radius of dividing holes are 70.182 mm and 80.663 mm. Increasing the height of the mould in the range of 61.282 mm to 70.422 mm can prolong its longevity, but when the height is over 70.422 mm, its longevity reduces.帅词俊 肖刚 倪正顺 钟掘 2003Journal of Central South University of Technology2003,10,1:8
14Recent Progress and Development in Extrusion of Rare Earth Free Mg Alloys: A Review显示文摘Mg and its alloys are the lightest structural metals available and are extremely attractive for applications as lightweight components, particularly in the automobile, electronic, and aerospace industries. The global market for wrought Mg alloys has steadily expanded over the past decade. And numerous studies have been carried out to meet this increasing demand of high-performance Mg alloys. However, Mg extrusion alloys have had a very limited usage so far. To overcome existing industrial challenges, one desirable approach is the development of low-cost rare earth(RE) free Mg extrusion alloys with superior mechanical properties. This review will introduce the recent research highlights in the extrusion of Mg alloys, specifi cally focusing on low-cost RE-free Mg alloy. The results from both the literature and our previous study are summarized and critically reviewed. Several aspects of RE-free Mg extrusion alloys are described in detail:(1) novel alloying designs including Mg–Al-, Mg–Zn-, Mg–Ca-, Mg–Sn-, and Mg–Bi-based alloys,(2) advanced extrusion techniques, and(3) extrusion-related severe plastic deformation(SPD) processing. Accordingly, considering the large gap in mechanical properties between the current RE-free Mg alloys and high-performance aluminum alloys, new alloy design, processing route control, and recommendations for future research on RE-free Mg extrusion alloys are also proposed. We hope this review will not only off er insightful information regarding the extrusion of RE-free Mg alloys but also inspire the development of new Mg extrusion technologies.Shuai-Ju Meng Hui Yu Shao-Da Fan Qi-Zhi Li Sung Hyuk Park Joung Sik Suh Young Min Kim Xiao-Long Nan Ming-Zhe Bian Fu-Xing Yin Wei-Min Zhao Bong Sun You Kwang Seon Shin 2019Acta Metallurgica Sinica(English Letters)2019,32,2:6
15A comprehensive review of extrusion-based additive manufacturing processes for rapid production of metallic and ceramic parts显示文摘The extrusion-based additive manufacturing (EAM) technique is recently being employed for rapid production of metals and ceramic components. This technique involves extruding the metal or ceramic material in solid powder form mixed with a binder (i.e., an expendable viscous fluid), which is removed from the part after 3D printing. These technologies rely on the large design freedom allowed and the cost efficiency advantage over alternative metal additive manufacturing processes that are based on high energy beams, such as laser or electron beams. The EAM of metals and ceramics is not yet widespread, but published scientific and technical literature on it is rapidly growing. However, this literature is still less extensive than that on the fused deposition modeling (FDM) of plastics or the selective laser melting (SLM) of metals. This paper aims at filling this gap. FDM and powder injection molding are identified as preceding or enabling technologies for EAM. This paper systematically reviews all aspects of the feedstock EAM processes used for production of complex-shaped parts. The unique characteristics and advantages of these processes are also discussed with respect to materials and process steps. In addition, the key process parameters are explained to illustrate the suitability of the EAM process for diverse application domains.Kedarnath Rane Matteo Strano 2019Advances in Manufacturing2019,7,2:6
16Microstructure and mechanical behavior of the Mg-Mn-Ce magnesium alloy sheets显示文摘The microstructural evolution and mechanical behavior of Mg-Mn-Ce magnesium alloy were investigated in the present study.Mg alloy was prepared with metal model casting method and subsequently hot extruded at 703 K with the reduction ratio of 101:1.The grains were dynamically recrystallized after the extrusion process.Moreover,the(0002)pole figure of Mg-Mn-Ce alloy developed a splitting of pronounced basal texture.The mechanical properties were different due to different angles between c-axis and loading direction(0°,45°and 90°)in the tensile tests.This significantly induces an asymmetry in the yield behavior.The Mg-Mn-Ce alloy exhibits a classical dimple structure as a result of slip accumulation and ductile tear.Qingshan Yang Bin Jiang Xin Li Hanwu Dong Wenjun Liu Fusheng Pan 2014Journal of Magnesium and Alloys2014,2,1:6
17TiAl ALLOYS PREPARED BY THERMAL EXTRUSION OF ELEMENTAL POWDER MIXTURES显示文摘TiAlALLOYSPREPAREDBYTHERMALEXTRUSIONOFELEMENTALPOWDERMIXTURES①LiuZhijian,QuXuanhui,HuangBaiyunPowderMetallurgyResearchInstitu...Liu Zhijian, Qu Xuanhui, Huang Baiyun Powder Metallurgy Research Institute, Central South University of Technology, Changsha 410083 1997中国有色金属学会会刊:英文版1997,7,1:6
18Effects of raw material extrusion and steam conditioning on feed pellet quality and nutrient digestibility of growing meat rabbits显示文摘This study was conducted to investigate the effects of raw material extrusion and steam conditioning on feed pellet quality and nutrient digestibility of growing meat rabbits, in order to determine appropriate rabbit feed processing methods and processing parameters. In Exp. 1, an orthogonal design was adopted.Barrel temperature, material moisture content and feed rate were selected as test factors, and acid detergent fiber(ADF) content was selected as an evaluation index to research the optimum extrusion parameters. In Exp. 2. a two-factor design was adopted. Four kinds of rabbit feeds were processed and raw material extrusion adopted optimum extrusion parameters of Exp. 1. A total of 40 healthy and 42-day-old rabbits with similar weight were used in a randomized design, which consisted of 4 groups and 10 replicates in each group(1 rabbits in each replicate). The adaptation period lasted for 7 d, and the digestion trial lasted for 4 d. The results showed as follows: 1) ADF was significantly affected by barrel temperature(P < 0.05); the optimum extrusion parameters were barrel temperature 125℃, moisture content 16% and feed rate 9 Hz. 2) Raw material extrusion and steam conditioning both significantly decreased powder percentage, pulverization ratio and protein solubility(P < 0.05), significantly improved hardness and starch gelatinization degree of rabbit feed(P < 0.05). They both had significant interaction effects on the processing quality of rabbit feed(P < 0.05). 3) Extrusion significantly improved the apparent digestibility of dry matter and total energy(P < 0.05). Extrusion and steam conditioning both significantly improved the apparent digestibility of crude fiber(CF), ADF and NDF(P < 0.05), but they had no interaction effects on the apparent digestibility of rabbit feed. Thus, using extrusion and steam conditioning technology at the same time in the weaning rabbits feed processing can improve the pellet quality and nutrient apparent digestibility of rabbit feed.Kuoyao Liao Jingyi Cai Zhujun Shi Gang Tian Dong Yan Delin Chen 2017Animal Nutrition2017,,2:6
19Long-term observation of the mineral trioxide aggregate extrusion into the periapical lesion:a case series显示文摘One-step apexification using mineral trioxide aggregate (MTA) has been reported as an alternative treatment modality with more benefits than the use of long-term calcium hydroxide for teeth with open apex. However, orthograde placement of MTA is a challenging procedure in terms of length control. This case series describes the sequence of events following apical extrusion of MTA into the periapical area during a one-step apexification procedure for maxillary central incisor with an infected immature apex. Detailed long-term observation revealed complete resolution of the periapical radiolucent lesion around the extruded MTA. These cases revealed that direct contact with MTA had no negative effects on healing of the periapical tissues. However, intentional MTA overfilling into the periapical lesion is not to be recommended.Seok-Woo Chang Tae-Seok Oh WooCheol Lee Gary Shun-Pan Cheung Hyeon-Cheol Kim 2013International Journal of Oral Science2013,5,1:5
20EXPERIMENTAL STUDY ON OPEN-DIE COLD EXTRUSION FORMING TECHNIQUE FOR INVOLUTESPLINE SHAFTS显示文摘EXPERIMENTALSTUDYONOPEN-DIECOLDEXTRUSIONFORMINGTECHNIQUEFORINVOLUTESPLINESHAFTSEXPERIMENTALSTUDYONOPEN-DIECOLDEXTRUSIONFORMIN...Zhang Zhenchun Li Jun Zhou Lihua Men Liantong ( Tianjin University) 1996Chinese Journal of Mechanical Engineering1996,9,1:5
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