葛向南朱达川冯作明
材料研究学报
用非自耗真空电弧炉熔炼β钛合金Ti--8Mo--8Zr--4.5Sn--2Mn, 用金相显微镜、X射线衍射仪、纳米硬度仪表征和研究了合金的组织、结构和弹性模量。结果表明: 这种β钛合金的组织中枝晶组织和等轴晶组织共存；晶体结构为β相, 合金元素产生了偏析; 合金的弹性模量为41.4 GPa。与TMA合金(Ti--11.5Mo--6Zr--4.5Sn)对照, 研究了电子浓度e/a、d电子理论参数结合次数Bo和d轨道能Md对合金弹性模量的影响。结果表明: 合金d轨道能Md值减小, 结合次数Bo减小, 同时电子浓度适当的增加, 有利于合金弹性模量的降低。
关键词:
金属材料
,
β–Ti alloy
,
elastic modulus
,
d–electron theory of alloys
,
electron concentration
衣虎春
,
葛庭燧
金属学报
测量了Mn-Cu-Al三元合金(含56-60wt-％Mn,0-3.59wt-％Al)在-150—150℃的声频内耗,发现当试样在调幅线的温度范围内进行时效时,内耗随着时效时间的增加而增加,并在特定的时间内达到极大值.时效温度越高,达到极大值的时间越短.在时效一定的时间后出现马氏体相变峰和孪晶界面弛豫峰.相变峰随着时效时间的增加而向高温移动;弛豫峰则出现在15℃左右(频率约1kHz),测得其激活能是0.56eV. 在调幅线内时效使合金的硬度、强度及脆性墙加,Al元素有增加合金的强度而降低其内耗的作用.实验结果表明,在450℃时效2—3h,可得到合金的内耗和强度的最佳综合指标. 根据内耗、模量、金相检验和X射线分析的结果,认为调幅分解后产生的富Mn区是合金发生相变和高内耗的来源,也是合金的强度增加和韧性降低的原因.
关键词:
Mn-Cu-Al合金
,
Mn-Cu-Al alloy
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elastic modulus
,
mechanical properties
,
aging
赵高敏
,
王昆林
,
刘家浚
金属学报
通过扫描电镜(SEM)研究了稀土氧化物La2O3对铁基合金激光熔覆层组织形貌的影响，用纳米硬度探针测定了熔覆层与基体界面附近和搭接区的硬度和弹性模量，并用MT--3型显微硬度计测试了多道熔覆层硬度的面分布。结果表明,稀土的加入细化了晶粒，减小了二次枝晶间距；近界面和搭接区的纳米硬度和弹性模量有不同程度的提高。硬度面分布测量结果表明，加入稀土后熔覆层的平均硬度(HV)约为500，比未加稀土的提高约50。本文还讨论了稀土作用的机理。
关键词:
激光熔覆
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rare earth
,
elastic modulus
Zhenjun Hong Jingchao Chen Jing Feng Yeping Du Jie Yu Lijuan Zhang Shuzhen Wu Futai Xu
材料科学技术（英）
The mechanical properties of nano-scale Cu/FeS composite were simulated by molecular dynamics (MD) simulation in this paper. Through the analysis on the stress-strain curves, the results of MD simulation were in good agreement with mechanisms of macroscopic deformation. When the size of particles was smaller than a certain value, the relationship between yield strength and size, which was different from the large size crystals abided by the contrary Hall-Petch relationship. Based on the discussion of nano-scale Cu/FeS composite, some interesting conclusions were obtained. For example, the "S" type curves were discovered in stress-strain curves and the anisotropy of FeS was very evident when the exposures of reinforcing phase (FeS) were different and so on. The basic theories and calculations of the composite that contains nano-scale particles were discussed. At the same time, a new modeling building method of composites, which was close to actual experiences, were considered in this paper.
关键词:
Nano-scale composite
,
mechanical properties
,
molecular dynamics simulation
,
elastic modulus
,
strain rigidity
YI Huchun GE Tingsui (T.S.Ke) Institute of Solid State Physics
,
Academia Sinica
,
Hefei
,
China GE Tingsui
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Professor
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Laboratory of Internal Friction and Defects in Solids
,
Institute of Solid State Physics
,
Academia Sinica
,
Hefei
,
China
金属学报(英文版)
Internal friction and elastic modulus of ternary Mn-Cu-Al alloys containing 56—60 wt-% Mn,0-3.59 wt-% Al were measured with acoustic frequency,1 kHz,in the tempera- ture range of-150 to 150℃.It was found that when the specimen was aged in the temperature range under the spinodal curve within the miscibility gap(400—500℃),the internal fric- tion increases with an increase of the aging time and reaches a maximum value at a certain ag- ing time which is shorter with a higher aging temperature.Two internal friction peaks which did not appear before the aging were observed above room temperature after a definite aging time.These are respectively the martensitic tranformation peak and the relaxation peak orig- inating from the stress-induced movement of the twin boundaries.The former peak shifts to- ward higher temperatures with an increase of the aging time,whereas the relaxation peak ap- pearing at 15℃,is independent of the aging time and temperature.The activation energy as- sociated with the relaxation peak was found to be 0.56 eV which is about the same as that of the relaxation peak in binary alloy containing 90 wt-% Mn.It was also found that the hardness,strength and the brittleness of the specimen increase when aged below the spinodal curve within the miscibility gap.The addition or Al enhances the strength but reduces the in- ternal friction of the specimen.A choice of suitable aging time and temperature can give an optimum compromise of high strength and high internal friction.Analysis of experimental re- sults suggests that spinodal decomposition leads to Mn-rich zones in the specimen and thus causes the phase transformation and the change of mechanical properties of the specimen.
关键词:
internal friction
,
null
,
null
,
null
,
null
吴翔
,
王日初
,
彭超群
,
蔡志勇
中国有色金属学报
采用热压法制备添加0～6％铜含量(质量分数)的Al-50％Sip(质量分数)复合材料,研究Cu含量对复合材料显微组织和力学性能的影响,对混合粉末进行差示扫描量热分析(DSC),采用扫描电镜(SEM)和X射线衍射仪(XRD)研究试样的显微组织和相组成,并测试复合材料的拉伸和抗弯性能.结果表明:单质Cu粉的加入降低混合粉末的熔点,有利于在相对较低的温度下实现材料的致密化.当Cu含量低于2％时,材料的组织均匀致密,Si颗粒未出现明显粗化;但当Cu含量高于2％时,组织均匀性随Cu含量的增加而逐渐下降;随着Cu含量增加,复合材料的抗拉强度和抗弯强度呈先上升后下降的趋势;在Cu含量为2％时,复合材料的抗拉强度和抗弯强度分别达到最大值(268和423 MPa),较未添加Cu的复合材料分别提高66.5％和46.9％,材料的弹性模量和布氏硬度随Cu含量的增加逐渐上升.
关键词:
铝硅复合材料
,
Al-50％Sip合金
,
热压
,
显微组织
,
抗拉强度
,
抗弯强度
,
弹性模量
,
硬度
陈茂林
,
许溱
,
朱玉田
,
刘钊
,
俞燕蕾
材料热处理学报
一种具有双向形变记忆功能的光致弯曲聚合物材料,在光驱动型执行器中应用潜力较大。材料的力学性能及光致弯曲特性,是执行器结构设计和分析的必要依据。通过拉伸实验,了解到材料具有线弹性材料类似的力学性能,并得到了其弹性模量。通过对材料光致弯曲效应的分析,推导出光致弯曲曲率的表达式。利用该公式,对光致弯曲实验观测到的数据进行非线性拟合,得到材料的光致弯曲特性参数。计算曲率较好地符合了实验数据,证明了公式和参数的合理性。
关键词:
光致弯曲
,
曲率
,
弹性模量
,
非线性拟合
杜圆明
,
张跃飞
,
张长辉
,
刘燕萍
稀有金属材料与工程
基于原子力显微镜(AFM)和扫描电子显微镜(SEM)建立了一套原位纳米压痕测试系统.该系统可以实现控制带有金刚石(Cube corner)压头的AFM微悬臂梁对样品进行压入实验,并得到载荷-位移曲线,同时可以对压痕过程进行原位SEM实时观察.发展了一种基于AFM微悬臂梁加载和原位SEM压痕图像分析的力学性能测试方法,通过测量压入最大载荷和原位SEM测量压痕残余面积得到塑性薄膜的硬度和弹性模量.利用此方法对磁控溅射硅衬底上纳米晶银薄膜进行了压痕实验,并与Nanoindenter G200型纳米压痕仪实验进行对比研究.结果表明,原位AFM压痕方法具有高的载荷和位移分辨率,可以实现纳牛至微牛级的压痕实验,通过测量压痕面积得到塑性薄膜的硬度值,减小了使用Oliver-pharr方法中软膜硬基底上凸起(Pile-up)效应的影响,计算结果也具有好的测试精度和可靠性.
关键词:
原子力显微镜
,
纳米压痕
,
硬度
,
弹性模量
宋小园
,
申向东
,
李红云
,
赵振亚
硅酸盐通报
弹性模量是砂浆的重要参数,为了研究水泥砂浆的早龄期弹性模量,配制了不同龄期、不同矿渣粉掺量、不同水胶比的砂浆试块.通过室内实验研究了水泥砂浆的早龄期弹性模量以及抗压强度与弹性模量的关系.实验结果显示:龄期、矿渣粉掺量、水胶比对掺矿渣粉水泥砂浆的弹性模量有明显影响,随着龄期的增长,抗压强度和弹性模量都增长,当固定矿渣掺量时,弹性模量随水胶比增大而减小;并根据实验结果得出了龄期和弹性模量的对数拟合公式.除此之外还探究了水泥砂浆弹性模量与强度之间的关系,提出了二者之间的经验公式.
关键词:
弹性模量
,
龄期
,
水胶比
,
矿渣粉
,
弹性模量与抗压强度关系
