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Deformation behavior and microstructure evolution of titanium alloys with lamellar microstructure in hot working process: A review 认领
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作者 Pengfei Gao Mingwang Fu +2 位作者 Mei Zhan Zhenni Lei Yanxi Li 《材料科学技术:英文版》 SCIE EI CAS CSCD 2020年第4期56-73,共18页
Titanium alloys have been widely used in many industrial clusters such as automotive, aerospace and biomedical industries due to their excellent comprehensive properties. In order to obtain fine microstructures and fa... Titanium alloys have been widely used in many industrial clusters such as automotive, aerospace and biomedical industries due to their excellent comprehensive properties. In order to obtain fine microstructures and favorable properties, a well-designed multi-step thermomechanical processing(TMP) is critically needed in manufacturing of titanium components. In making of titanium components,subtransus processing is a critical step to breakdown lamellar microstructure to fine-structure in hot working process and thus plays a key role in tailoring the final microstructure and properties. To realize this goal, huge efforts have been made to investigate the mechanisms of microstructure evolution and flow behavior during the subtransus processing. This paper reviews the recent experimental and modelling progresses, which aim to provide some guidelines for the process design and microstructure tailoring for titanium alloy research community. The characteristics of the initial lamellar microstructure are presented, followed by the discussion on microstructure evolution during subtransus processing. The globularization of lamellar α is analyzed in detail from three aspects, i.e., globularization mechanism, heterogeneity and kinetics. The typical features of flow behaviors and the explanations of significant flow softening are then summarized. The recent advances in modelling of microstructure evolution and flow behaviors in the subtransus processing are also articulated. The current tantalized issues and challenges in understanding of the microstructure evolution and flow behaviors of the titanium alloys with lamellar microstructure are presented and specified in future exploration of them. 展开更多
关键词 TITANIUM alloys LAMELLAR MICROSTRUCTURE Deformation behavior MICROSTRUCTURE evolution
Effect of Cu-Ni and Cu-Ni-Mn on the Microstructural and Mechanical Behaviour of As-Cast Non-Inoculated Hypereutectic Grey Iron 认领
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作者 Seidu Ojo Adama Sumaila Onigbajumo Adetunji 《矿物质和材料特性和工程(英文)》 2020年第2期27-46,共20页
The hypereutectic region of grey cast iron has received very little attention especially for designing cast products by researchers. Due to its high carbon equivalence, hypereutectic grey iron poses some challenges es... The hypereutectic region of grey cast iron has received very little attention especially for designing cast products by researchers. Due to its high carbon equivalence, hypereutectic grey iron poses some challenges especially its tendency for grey to white transition (GWT) at this level of carbon content. However, hypereutectic grey iron possesses inherent properties that could be easily utilized for improved performance in automobile engines and brake pad system. Significantly, they could be modified for superior hardness, strength and toughness. This study presents the effect of microalloying on the mechanical behaviour of hypereutectic grey cast iron with carbon equivalence above 4.5. The first part of this work presented in this paper considers the addition of Cu-Ni and Cu-Ni-Mn to series of as-cast hypereutectic grey cast iron and their hardness and tensile strength were studied and compared. A total of 33 cast samples were obtained with the control sample. The examination of the micrographs revealed that graphite eutectics cells of Type A and A + D were obtained in the resulting microstructure. Results analyses showed that the ferrite forming tendency of silicon was suppressed due to the high carbon content of the as-cast hypereutectic grey iron coupled with the absence of inoculation which plays a great role in the graphite flake type, network, size and distribution. Cu-Ni microalloying was also confirmed to promote hardness with the hardening effect limit of nickel observed at 1.3% composition. For Cu-Mi-Mn addition, excess and free sulphur in the hyper- eutectic grey iron results in reverse effect of manganese on strength, hardness, reduced graphite flake size and shape. 展开更多
关键词 HYPEREUTECTIC Grey IRON Microstructure Hardness Tensile Strength Inoculation GRAPHITIZATION Cast IRON Alloying
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大鼠“曲泽”,“大陵”和“中冲”穴区之间神经血管显微结构的比较 认领
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作者 张知云 徐东升 +4 位作者 张建梁 王佳 崔晶晶 景向红 白万柱 《世界针灸杂志:英文版》 CSCD 2020年第1期61-64,共4页
Objective:The aim of this study was to compare the microstructure of blood vessels and nerve fibers between different acupoints in the rat skin from the perspective of histology.Methods:The skin tissue at"Quze&qu... Objective:The aim of this study was to compare the microstructure of blood vessels and nerve fibers between different acupoints in the rat skin from the perspective of histology.Methods:The skin tissue at"Quze"(曲泽PC3)""Daling(大陵PC7)"and"Zhongchong(中冲PC9)"regions was taken from the rat forelimb along the pericardium meridian,and cut sagittally with a freezing microtome.After that,the skin sections were stained by fluorescent histochemistry and immunohistochemistry with phalloidin and calcitonin gene-related peptide(CGRP)to reveal the microstructure of blood vessels and nerve fibers respectively,and then examined under a laser scanning confocal microscope.Results:The microstructure of blood vessels and nerve fibers was clearly labeled with phalloidin and CGRP,respectively.The blood vessels and nerve fibers were observed in the dermis of"PC3""PC7"and"PC9"regions,where the bundle of nerve fibers distribute in parallel to the blood vessels,and sent out thin branches to surround the wall of the blood vessels.In contrast,the density of blood vessels and nerve fibers in"PC3""PC7"and"PC9"were presented orderly in an increased tendency.Conclusion:The results of present study demonstrate the differences of the neurovascular microstructure among"PC3""PC7"and"PC9"in the rat,providing a histological view to insight into the specificity of different acupoints. 展开更多
关键词 SKIN Calcitonin gene-related peptide Phalloidin The microstructure of blood vessels The microstructure of nerve fibers Histology on acupoints
ZrO2陶瓷显微结构对绿光飞秒激光加工过程的协同效应 认领
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作者 吕健 王宏建 +6 位作者 曹佐 袁莉娟 李冰 左飞 周锐 谢庆丰 林华泰 《人工晶体学报》 EI CAS 北大核心 2020年第2期305-311,330共8页
氧化锆(ZrO2)陶瓷因其性能优异,常被应用于医学与工业等领域。通过表面微纳加工可进一步发挥其性能优势,扩大应用范围。实验采用绿光飞秒激光对具有不同显微结构的ZrO2陶瓷基体进行微孔加工,结合显微结构差异对材料物理性能的影响,系统... 氧化锆(ZrO2)陶瓷因其性能优异,常被应用于医学与工业等领域。通过表面微纳加工可进一步发挥其性能优势,扩大应用范围。实验采用绿光飞秒激光对具有不同显微结构的ZrO2陶瓷基体进行微孔加工,结合显微结构差异对材料物理性能的影响,系统研究了激光加工功率与加工时间等工艺参数对微孔形貌、直径及深度等不同维度下形貌学特征的作用效果。结果表明,同一加工参数下,晶粒更小、显微结构更均匀、热导率更低的ZrO2具有更高的加工效率;通过对比微孔直径与深度随激光加工工艺参数的变化,发现材料显微结构的差异对微孔轴向的影响比径向更加显著。 展开更多
关键词 氧化锆 显微结构 绿光飞秒激光 表面微结构
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<i>In Situ</i>Synthesis of Titanium Carbide in Pure Aluminium 认领
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作者 Satish Babu Boppana 《材料科学与化学工程(英文)》 2020年第1期1-10,共10页
The present work reports on the mechanism of formation of TiC in pure Aluminium melt. A halide salt of Al3TiF6, graphite powder and pure Al were used to prepare in situ Al-TiC Metal Matrix Composites (MMCs). Scanning ... The present work reports on the mechanism of formation of TiC in pure Aluminium melt. A halide salt of Al3TiF6, graphite powder and pure Al were used to prepare in situ Al-TiC Metal Matrix Composites (MMCs). Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to determine the microstructural characteristics of the composite. XRD was further used to determine the phases involved in the composite for confirming the formation of TiC. Further to assess the mechanism involved in the in situ reactions, DTA/TGA thermograms were used to analyze the reactions between molten Al, halide salt and graphite powder. Tensile tests were conducted to study the fracture behavior of the in situ prepared MMCs. 展开更多
关键词 In SITU TiC Microstructure TENSILE Strength FRACTURE Analysis
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离心铸造AZ81镁合金的组织结构和力学性能研究 认领
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作者 铁争鸣 李广德 《热加工工艺》 北大核心 2020年第5期87-89,共3页
分别采用离心铸造和金属型重力铸造制备了AZ81镁合金试样,并对两种试样的晶粒结构、第二相分布与拉伸性能、硬度等进行了比较。试验结果表明,与金属型重力铸造相比,离心铸造试件的晶粒明显细化,抗拉强度、屈服强度、伸长率有明显提高,... 分别采用离心铸造和金属型重力铸造制备了AZ81镁合金试样,并对两种试样的晶粒结构、第二相分布与拉伸性能、硬度等进行了比较。试验结果表明,与金属型重力铸造相比,离心铸造试件的晶粒明显细化,抗拉强度、屈服强度、伸长率有明显提高,显微硬度有所提高。 展开更多
关键词 离心铸造 AZ81镁合金 显微组织 力学性能
澎内传防水涂层在大坝混凝土防渗墙中的应用 认领
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作者 郭凤娟 王慧 +1 位作者 焦照峰 孙玉清 《水电能源科学》 北大核心 2020年第1期74-77,共4页
为了研究澎内传防水剂涂料对大坝防渗墙混凝土性能的改良效果,设计了4种浓度的澎内传防水剂的混凝土涂层,对改性试样开展渗透试验、高速水流冲蚀试验和强度试验,并进行微观结构的SEM扫描,以此分析了混凝土性能与内部结构的关系。结果表... 为了研究澎内传防水剂涂料对大坝防渗墙混凝土性能的改良效果,设计了4种浓度的澎内传防水剂的混凝土涂层,对改性试样开展渗透试验、高速水流冲蚀试验和强度试验,并进行微观结构的SEM扫描,以此分析了混凝土性能与内部结构的关系。结果表明,防水剂的浓度越大,混凝土防渗性能的改善效果越好,浓度为3.0%的涂层对试样防渗效果最佳;冲蚀程度随着防水剂浓度增大呈先降低后稳定的特点;混凝土的抗压强度和弹性模量几乎不受防水剂浓度的影响;澎内传防水剂对试样内部孔隙结构的改变非常显著,经防渗涂层处理后的混凝土密实程度大幅提高。 展开更多
关键词 澎内传防水涂层 防渗性能 混凝土 微观机理
超音速微粒轰击对Q355NH耐候钢表面结构及电化学腐蚀性能的影响 认领
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作者 杨军 谢小龙 +1 位作者 汪蓬勃 邹德宁 《矿冶工程》 CAS CSCD 北大核心 2020年第1期130-133,137共5页
利用超音速微粒轰击(SFPB)技术在Q355NH耐候钢表面制备了梯度纳米结构层。采用光学显微镜、扫描电镜、X射线衍射仪和显微硬度仪表征并分析了SFPB处理时间(15 min、30 min和45 min)对试验钢微观组织及电化学腐蚀行为的影响。结果表明,随... 利用超音速微粒轰击(SFPB)技术在Q355NH耐候钢表面制备了梯度纳米结构层。采用光学显微镜、扫描电镜、X射线衍射仪和显微硬度仪表征并分析了SFPB处理时间(15 min、30 min和45 min)对试验钢微观组织及电化学腐蚀行为的影响。结果表明,随着SFPB处理时间增加,试样表面强烈塑性变形层厚度相应增加,表面晶粒尺寸分别为27.5 nm、24 nm和23.1 nm,表面硬度呈现不同程度地增加。试样的耐电化学腐蚀性能强弱与处理时间的关系如下:15 min试样>未处理试样>30 min试样>45 min试样。从表面腐蚀形貌可以得出,处理15 min的试样表面保护性的钝化膜较为致密,而其他不同状态下的试样钝化膜则相对出现一些裂纹和孔洞。 展开更多
关键词 表面改性 表面处理 耐候钢 超音速微粒轰击 表面纳米化 腐蚀性能 微观组织
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双层预烧结新工艺传热与成矿行为研究 认领
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作者 周明顺 王义栋 +3 位作者 赵东明 翟立委 姜涛 钟强 《烧结球团》 北大核心 2020年第1期13-19,共7页
在没有富氧烧结的条件下,在本研究的前期工作中对预烧结时间与双层布料上、下层厚度的比例关系进行了优化实验并开展了工业试验,取得了双层烧结大幅增产的效果,烧结矿质量满足高炉冶炼要求。但双层预烧结工艺存在下层烧结矿强度差的问题... 在没有富氧烧结的条件下,在本研究的前期工作中对预烧结时间与双层布料上、下层厚度的比例关系进行了优化实验并开展了工业试验,取得了双层烧结大幅增产的效果,烧结矿质量满足高炉冶炼要求。但双层预烧结工艺存在下层烧结矿强度差的问题,针对该问题开展了双层预烧结传热与成矿行为的研究,结果表明:双层预烧结热状态烟气性质与单层烧结完全不同,其烧结料层结构和性质更为复杂;双层预烧结料层中下部反应气体为上层废气,含氧量低,导致中下部部分区域烧结矿矿化不充分,烧结矿结构有些疏松;双层预烧结上部料层为单层烧结过程,中部料层为预烧结形成的烧结矿带,该料层烧结过程与单层一致;下部料层与上部料层同步进行烧结的双层预烧结过程,其传热与成矿行为与常规的单层烧结完全不同。本研究工作将为后续改善双层预烧结工艺烧结矿质量提供理论支撑。 展开更多
关键词 双层预烧结 热量传递 成矿行为 微观结构
空间微重力条件下偏晶合金凝固研究进展 认领
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作者 江鸿翔 黎旺 +2 位作者 张丽丽 何杰 赵九洲 《中国科学:物理学、力学、天文学》 CSCD 北大核心 2020年第4期83-90,共8页
偏晶合金种类很多,若能将其制成具有理想组织结构的原位复合材料,则它们之中许多均具有优异的性能和重要的工业应用前景.然而,当均匀、单相的偏晶合金熔体冷却进入液态组元不混溶区间时会发生液-液相变,生成互不混溶的两个液相.在地面... 偏晶合金种类很多,若能将其制成具有理想组织结构的原位复合材料,则它们之中许多均具有优异的性能和重要的工业应用前景.然而,当均匀、单相的偏晶合金熔体冷却进入液态组元不混溶区间时会发生液-液相变,生成互不混溶的两个液相.在地面常规重力条件下冷却凝固时,熔体内往往存在较强的对流且两个液相间通常具有较大的密度差,这使得该类合金非常容易形成相偏析严重、甚至两相分层的组织.在微重力条件下冷却凝固时,由重力对流和组元间密度差引起的两相分离现象得到明显减弱,有利于该类合金凝固理论的研究和弥散型偏晶基复合材料的制备.近年来,有关微重力条件下偏晶合金凝固理论及组织控制的研究受到了材料科学领域的高度关注,人们在空间微重力条件下和地面模拟微重力条件下开展了大量的研究工作.本文综述了近年来微重力条件下偏晶合金凝固研究的进展. 展开更多
关键词 偏晶合金 组织 微重力 凝固
热处理对超音速火焰喷涂FeAl-Al涂层组织结构的影响 认领
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作者 向军淮 吴志诚 +2 位作者 彭文屹 白凌云 刘学璋 《表面技术》 EI CAS CSCD 北大核心 2020年第5期98-102,154,共6页
目的通过超音速火焰喷涂(High Velocity Oxygen Fuel,HVOF)的粉末喂料设计,获取结构致密的铁铝金属间化合物涂层,并详细考察热处理对所制备涂层组织结构的影响。方法在铁铝合金粉末喂料中添加质量分数为5%的铝粉,改善喷涂效果,在316L不... 目的通过超音速火焰喷涂(High Velocity Oxygen Fuel,HVOF)的粉末喂料设计,获取结构致密的铁铝金属间化合物涂层,并详细考察热处理对所制备涂层组织结构的影响。方法在铁铝合金粉末喂料中添加质量分数为5%的铝粉,改善喷涂效果,在316L不锈钢表面制备致密的FeAl-Al涂层,并进行真空热处理。采用X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、能谱仪(EDS)及维氏显微硬度计,详细分析了涂层在不同热处理温度下的微观组织、成分、结构与显微硬度的变化。结果喷涂态FeAl-Al涂层厚度约为150μm,物相为Fe2Al5,未检测到单质Al。随着热处理温度升高,Fe2Al5相的衍射峰逐渐增强。500℃热处理后,喷涂态涂层中扁平粒子间存在的细微孔隙大量消失,涂层致密性明显提高。但是800℃热处理后,涂层中产生了与界面平行的裂纹。喷涂态FeAl-Al涂层的硬度为465.06HV0.1,500℃热处理2 h后增加至472.06HV0.1,继续提高热处理温度,涂层的显微硬度则明显下降。结论在粉末喂料中引入质量分数为5%的Al粉,可明显改善超音速火焰喷涂效果,获得结构致密、与基体结合牢固的FeAl-Al涂层。合适的热处理能进一步消除喷涂缺陷,使涂层显微硬度增加,微观结构更加致密。 展开更多
关键词 超音速火焰喷涂 FEAL金属间化合物 FeAl-Al涂层 热处理 组织结构 显微硬度
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2014铝合金轧制工艺研究 认领
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作者 李大伟 张磊 +1 位作者 周远航 付威 《热加工工艺》 北大核心 2020年第3期110-112,共3页
通过显微组织观察、拉伸性能测试研究了轧制温度、轧制变形量对2014铝合金显微组织和力学性能的影响。结果表明:当变形量60%且轧制温度400~460℃时,随着轧制温度的升高,组织中再结晶晶粒逐渐减少,420℃轧制试样组织均匀,晶粒尺寸最小。... 通过显微组织观察、拉伸性能测试研究了轧制温度、轧制变形量对2014铝合金显微组织和力学性能的影响。结果表明:当变形量60%且轧制温度400~460℃时,随着轧制温度的升高,组织中再结晶晶粒逐渐减少,420℃轧制试样组织均匀,晶粒尺寸最小。随着轧制温度的升高,试样强度和伸长率先升高再降低,420℃轧制试样的强度和伸长率达到最大值。当轧制温度420℃且变形量20%~80%时,随着变形量的增加,试样铸态枝晶状组织逐渐减少,抗拉强度和伸长率先增大后减小,屈服强度变化不明显。当变形量60%时,试样力学性能最优。 展开更多
关键词 2014铝合金 轧制 显微组织 力学性能
Influence of Si Contents on the Microstructure Evolution and Mechanical Properties of Al Mg Si Cu Zn Alloys 认领
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作者 Liang Zhu Mingxing Guo +3 位作者 Jishan Zhang Gaojie Li Yu Wang Linzhong Zhuang 《哈尔滨工业大学学报:英文版》 EI CAS 2020年第1期10-18,共9页
The influence of different Si contents on the microstructure evolution and mechanical properties of Al Mg Si Cu Zn alloys was systematically studied using tensile testing,OM,SEM,EDS,and EBSD.The results indicate that ... The influence of different Si contents on the microstructure evolution and mechanical properties of Al Mg Si Cu Zn alloys was systematically studied using tensile testing,OM,SEM,EDS,and EBSD.The results indicate that the grain size of as cast alloys was gradually reduced with the increase of the Si content,which mainly resulted from the formation of many iron rich phases and precipitates during the casting process.During homogenization treatment,the plate likeβ AlFeSi phases in the alloy with a higher Si content easily transformed to the sphericalα Al(FeMn)Si phases,which is helpful for improving the formability of alloys.The microstructure evolution of the alloys was also greatly dependent on the content of Si that the number density and homogeneous distribution level of precipitates in the final cold rolled alloys both increased with the increase of the Si content,which further provided a positive effect on the formation of fine recrystallization grains during the subsequent solution treatment.As a result,the yield strength,ultimate tensile strength,and elongation of the pre aged alloys in the direction of 45°with respect to the rolling direction were all increased with increasing Si content. 展开更多
关键词 AL Mg SI CU ZN alloy Mg/Si ratio microstructure evolution MECHANICAL properties
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时效时间对ZA35-1.35Si-0.3Zr合金组织及电化学性能的影响 认领
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作者 刘敬福 付文达 《兵器材料科学与工程》 CAS CSCD 北大核心 2020年第1期83-86,共4页
用金相显微镜、XRD、扫描电镜以及电化学工作站,研究不同时效时间对ZA35-1.35Si-0.3Zr合金组织和电化学性能的影响。结果表明:固溶时效处理可以有效减小ZA35-1.35Si-0.3Zr合金晶粒尺寸,提高其电化学性能;时效时间为6 h时,合金晶粒尺寸最... 用金相显微镜、XRD、扫描电镜以及电化学工作站,研究不同时效时间对ZA35-1.35Si-0.3Zr合金组织和电化学性能的影响。结果表明:固溶时效处理可以有效减小ZA35-1.35Si-0.3Zr合金晶粒尺寸,提高其电化学性能;时效时间为6 h时,合金晶粒尺寸最小,第二相数量明显增多且颗粒细小、分布均匀;在6 h时效时间下合金的电化学性能最好,腐蚀电流密度比铸态ZA35-1.35Si-0.3Zr合金降低71.9%;时效处理ZA35-1.35Si-0.3Zr合金在质量分数为3.5%的NaCl溶液中电化学性能增强的主要原因是合金的容抗弧变大,极化电阻增加,腐蚀速率降低。 展开更多
关键词 ZA35-1.35Si-0.3Zr合金 时效时间 显微组织 电化学性能
304不锈钢扁平头半空心厚壁铆钉翻铆缺陷分析 认领
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作者 杨程 牛艳 +2 位作者 王瑞静 姚杰 康佳 《塑性工程学报》 CAS CSCD 北大核心 2020年第3期65-71,共7页
为了揭示304不锈钢扁平头半空心厚壁铆钉在翻铆过程中易出现压不到位、空心壁开裂和腰部镦粗等缺陷产生的原因,采用有限元、机理分析和实验的方法分析了半空心厚壁铆钉的制作及翻铆过程,获得了铆钉制作及翻铆时铆钉的应力场、硬度分布... 为了揭示304不锈钢扁平头半空心厚壁铆钉在翻铆过程中易出现压不到位、空心壁开裂和腰部镦粗等缺陷产生的原因,采用有限元、机理分析和实验的方法分析了半空心厚壁铆钉的制作及翻铆过程,获得了铆钉制作及翻铆时铆钉的应力场、硬度分布和显微组织。结果表明:翻铆时翻卷半径过小,材料在弯角内侧堆积,导致压不到位。铆钉空心壁在铆钉制作和翻铆过程中变形量最大,加工硬化最严重,且有部分马氏体相变,导致铆钉空心壁部分的伸长率大幅下降;翻铆时铆钉空心壁外翻直径过大,超过拉伸极限,则铆钉在硬度最高的空心壁处开裂。铆钉制作和翻铆时腰部变形量最小,硬度最低,当翻铆力大于其抗压缩失稳的能力时,则会在腰部发生镦粗。 展开更多
关键词 304不锈钢 扁平头半空心铆钉 翻铆 加工硬化 显微组织
SiCf/Ti/Ti2AlNb叠层复合材料制备及组织性能 认领
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作者 金旗 任学平 +4 位作者 李殊霞 张国庆 曲海涛 赵冰 侯红亮 《塑性工程学报》 CAS CSCD 北大核心 2020年第3期72-80,共9页
针对目前航空航天材料结构轻量化的要求,以连续SiC纤维、Ti箔和Ti2AlNb箔为原材料,基于真空热压技术,采用Foil-Fiber-Foil法,通过优化制备工艺,获得SiCf/Ti/Ti2AlNb叠层复合材料。利用扫描电镜和能谱分析仪对制备的复合材料界面微观组... 针对目前航空航天材料结构轻量化的要求,以连续SiC纤维、Ti箔和Ti2AlNb箔为原材料,基于真空热压技术,采用Foil-Fiber-Foil法,通过优化制备工艺,获得SiCf/Ti/Ti2AlNb叠层复合材料。利用扫描电镜和能谱分析仪对制备的复合材料界面微观组织进行分析,通过密度测试和拉伸试验计算材料的比强度和比刚度。结果表明,在920℃、40 MPa下保温保压1 h,可获得理想的SiCf/Ti/Ti2AlNb叠层复合材料,SiC纤维排布均匀,Ti/Ti2AlNb界面平直。其中,SiC/Ti界面为0.8μm的TiC,而Ti/Ti2AlNb界面为α+β双相组织和富B2相,均形成良好的冶金结合,有利于载荷传递,保证材料性能。与Ti/Ti2AlNb相比,制备的SiCf/Ti/Ti2AlNb叠层复合材料的比强度和比刚度分别提高了约16%和28%,实现了材料结构的轻量化。 展开更多
关键词 SIC纤维 Foil-Fiber-Foil法 叠层复合材料 真空热压技术 微观组织
能量配比对S355ML钢激光-MAG复合焊的影响 认领
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作者 刘福运 李国豪 +5 位作者 檀财旺 吴来军 陈波 汪彬 宋晓国 冯吉才 《热加工工艺》 北大核心 2020年第1期19-23,共5页
对5 mm厚S355ML细晶粒结构钢进行激光-MAG复合焊,在保证线能量为400 J/mm的情况下,研究激光能量占总能量的能量配比(ER)对焊接接头宏观成形、显微组织及硬度、拉伸等力学性能的影响。结果表明,ER=0.2时,焊缝出现未熔透缺陷,且焊缝上下... 对5 mm厚S355ML细晶粒结构钢进行激光-MAG复合焊,在保证线能量为400 J/mm的情况下,研究激光能量占总能量的能量配比(ER)对焊接接头宏观成形、显微组织及硬度、拉伸等力学性能的影响。结果表明,ER=0.2时,焊缝出现未熔透缺陷,且焊缝上下部硬度分布不均匀;ER=0.4和0.6时,焊缝均成形良好,且硬度分布均匀。拉伸接头均断裂于母材,表明焊缝强度高于母材。另外,焊缝截面呈"高脚杯"状,分为电弧区和激光区,热影响区分为过热区和重结晶区。焊缝区组织主要为铁素体和珠光体,过热区组织主要为粗大的魏氏组织和贝氏体,重结晶区组织主要为等轴铁素体和珠光体。 展开更多
关键词 激光-MAG复合焊 S355ML 能量配比 力学性能 显微组织
Influence of minor Ce additions on the microstructure and mechanical properties of Mg-1.0Sn-0.6Ca alloy 认领
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作者 Yanfu Chai Chao He +7 位作者 Bin Jiang Jie Fu Zhongtao Jiang Qingshan Yang Haoran Sheng Guangsheng Huang Dingfei Zhang Fusheng Pan 《材料科学技术:英文版》 SCIE EI CAS CSCD 2020年第2期26-37,共12页
The microstructure and mechanical properties of Mg-Sn-Ca-Ce alloys with different Ce contents(0.0,0.2,0.5,1.0 wt%)were studied at room temperature.Ce additions to ternary Mg-Sn-Ca alloy resulted in grain refinement as... The microstructure and mechanical properties of Mg-Sn-Ca-Ce alloys with different Ce contents(0.0,0.2,0.5,1.0 wt%)were studied at room temperature.Ce additions to ternary Mg-Sn-Ca alloy resulted in grain refinement as well as a change in the category of second phase from CaMgSn to(Ca,Ce)Mg Sn and Mg12Ce.The volume fraction of second phase increased with rising Ce content,which aggravated the restriction of DRXed grain growth during the extrusion process and eventually led to texture weakening of as-extruded Mg-Sn-Ca based alloys.In terms of plasticity,owing to vigorously activated basal slip and homogeneous distributed tensile strain in tension,the tensile ductility of as-extruded alloys reached the maximum value of 27.6%after adding 0.2 wt%Ce,which enhanced by about 26%than that of ternary MgSn-Ca alloy.However,further Ce additions(0.5 and 1.0 wt%)would coarsen the second phase particles and then impair ductility.The tension-compression yield asymmetry of as-extruded Mg-Sn-Ca ternary alloy was alleviated greatly via Ce additions,due to the joint effects of grain refinement,increased amount of strip distributed second phase particles and texture weakening. 展开更多
关键词 Mg-Sn-Ca alloy Ce content Microstructure TEXTURE Mechanical properties
抽拉速率对定向凝固镍基高温合金组织和偏析的影响 认领
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作者 梅自寒 强军锋 +2 位作者 余竹焕 刘蓓蕾 费祯宝 《铸造技术》 CAS 2020年第4期313-318,共6页
研究了抽拉速率对一种定向凝固镍基高温合金组织与偏析的影响。结果表明,随着抽拉速率的增加,固液界面由平界面向胞状,再到粗枝状,最后到细枝状的演变过程,枝晶不断细化;一次和二次枝晶间距不断变小,γ′相形貌越来越呈规则的立方体,γ... 研究了抽拉速率对一种定向凝固镍基高温合金组织与偏析的影响。结果表明,随着抽拉速率的增加,固液界面由平界面向胞状,再到粗枝状,最后到细枝状的演变过程,枝晶不断细化;一次和二次枝晶间距不断变小,γ′相形貌越来越呈规则的立方体,γ′尺寸逐渐变小。元素偏析程度先增大后减小,并在100μm/s时到达峰值;共晶和碳化物尺寸均随着抽拉速率的增大而变小,碳化物和共晶体积分数随抽拉速率增大而增大。 展开更多
关键词 定向凝固 抽拉速率 高温合金 组织 偏析
Microstructure,Texture Evolution,and Mechanical Properties of ECAP-Processed ZAT522 Magnesium Alloy 认领
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作者 Ying Ma Fu-Yin Han +1 位作者 Cheng Liu Ming-Zhe Li 《金属学报:英文版》 SCIE EI CAS CSCD 2020年第2期233-242,共10页
In this work,the high-strength Mg-5Zn-2Al-2Sn(ZAT522,in wt%) Mg alloys was obtained at 220℃ and 130℃ by a two-step equal channel angular pressing(ECAP).For each stage,two passes were used.The results showed a remark... In this work,the high-strength Mg-5Zn-2Al-2Sn(ZAT522,in wt%) Mg alloys was obtained at 220℃ and 130℃ by a two-step equal channel angular pressing(ECAP).For each stage,two passes were used.The results showed a remarkable grain refinement after the first stage of ECAP(A2 samples),leading to a fine-grained structure with average size of 1.40 μm.The additional stage(A4 samples) caused further grain refinement to 1.18 μm,and an ultra-fine grain structure(700 nm)appeared in the precipitate-rich region.The grain refinement mechanism for both samples was discussed in detail.To this end,the original extrusion fiber texture evolved into a new strong texture characterized by the base planes tilted toward the ECAP shear plane,with a higher Schmid factor value of 0.34.Compared with the as-extruded alloy,the yield strength of the A2 samples increased from 180 to 245 MPa,which was mainly attributed to the combined effects of grain boundary strengthening and precipitation strengthening.In the case of A4 samples,the dislocation strengthening resulted in a net increase in yield strength to 335 MPa,while the ductility was significantly reduced. 展开更多
关键词 Mg–5Zn–2Al–2Sn Mg alloy ECAP MICROSTRUCTURE Texture Tension properties
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