Kai Wu
,
Jin-Yu Zhang
,
Gang Liu
,
Jiao Li
,
Guo-Jun Zhang
,
Jun Sun
金属学报(英文版)
doi:10.1007/s40195-016-0375-4
An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films (NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be ~5.0 J/m2 for Cu/Cr, ~4.1 J/m2 for Cu/Ta, ~2.8 J/m2 for Cu/Mo, ~1.1 J/m2 for Cu/Nb, and ~1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.
关键词:
niaxial
,
tensile
,
testing
,
Nanostructured
,
multilayer
,
films
,
Flexible
,
substrates
,
Buckling
,
behaviors
,
Adhesion
,
energy
Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science
The hydrogenation behavior of Ti-6Al-4V, with the starting microstructures of coarse equiaxed alpha and coarse Widmanstatten alpha, respectively, was investigated under a hydrogen pressure of 0.1 MPa at temperatures between 843 and 1123 K. The hydrogen content was determined as a function of hydrogenation time, hydrogenation temperature, and hydrogen flow rate. The phases presented in the alloy of after hydrogenation were determined with X-ray and electron diffraction analysis in order to define the effect of Thermochemical Processing (TCP) on the microstructure of the alloy. Mechanical properties and fracture toughness of Ti-6Al-4V and Ti-5A1-2.5Fe subjected to the various TCP were then investigated. Hydrogenation of Ti-6Al-4V with the starting microstructure of coarse equiaxed (alpha at 1023 K, just below hydrogen saturated beta (denoted beta (H)) transus temperature, produces a microstructure of alpha, orthohombic martensite (denoted alpha'' (H)) and beta (H). Hydrogenation at 1123 K, above beta (H) transus, results in a microstructure of alpha'' (H) and beta (H). Microstructure refinement during TCP results mainly from decomposition of (alpha'' (H) and beta (H) into a fine mixture of alpha + beta during dehydrogenation. An alternative TCP method is below beta (H) transus hydrogenation (BTH), consisting of hydrogenation of the alloy below the hydrogenated beta (H) transus temperature, air cooling to room temperature, and dehydrogenation at a lower temperature, which is found to improve mechanical properties significantly over a conventional TCP treatment. Compared with the untreated material, the BTH treatment increases the yield strength and increases the ultimate tensile strength significantly without decreasing the tensile elongation in the starting microstructure of coarse equiaxed alpha or with a little decrease in the tensile elongation in the starting microstructure of coarse Widmanstatten alpha, although the conventional TCP treatment results in a large decrease in elongation over the unprocessed material in Ti-6Al-4V. In Ti-5Al-2.5 Fe, both conventional TCP and BTH result in a increase in yield strength, ultimate tensile strength, and elongation; however, the BTH gives the best balance between strength and elongation. The TCP-treated Ti-6Al-4V shows smaller fracture toughness compared with the unprocessed material, while TCP-treated Ti-5A1-2.5Fe shows greater fracture toughness compared with the unprocessed material. The BTH treatment results in a improvement in fatigue strength in both Ti-6Al-4V and Ti-5Al-2.5Fe.
关键词:
tensile
W.Huang
,
X.Nie
,
X.Zan
,
Y.M.Xia
金属学报(英文版)
A new experimental technique has been developed for the performance of high temperature, high-strain rate tensile experiments in the self-designed tensile impact apparatus. This technique uses rapid contact heating method to heat the specimen to the desired temperature, thus avoids a significant temperature rise in incident and transmitted bars, and at the same time it is capable of retaining a nearly homogeneous temperature field within the specimen. As an illustration of its application, the hightemperature response of the forging die steel 5CrMnMo at high strain rates has been examined. Stress-strain curves are obtained for this material at strain rates ranging from 230s^-1 to 1200s^-1 and at temperature ranging from 25 to 606PC, respectively. For comparison, quasi-static experiments are performed over a slightly smaller range of temperatures.
关键词:
elevated temperature
,
null
,
null
潘巧灵
,
蒋金华
,
唐渝思
,
卓东方
,
吴丽婷
,
陈南梁
玻璃钢/复合材料
为了研究球形陆基充气天线球面材料力学性能,在标准实验室环境里,对高强涤纶丝平纹PVC膜结构材料进行拉伸、撕裂、顶破力学性能测试;用乐泰401胶水胶接PVC膜结构材料,对不同胶接长度的材料进行拉伸性能测试;对材料在20％的盐酸和氢氧化钠溶液中腐蚀不同周期后进行拉伸性能测试.实验结果表明,球面材料经向断裂强力大于纬向;随着胶接长度的增加,断裂强力先显著增加,后趋于平缓;随着碱蚀时间的增加,沿经向和纬向的断裂强力都下降,但沿纬向的断裂强力下降幅度大于经向;PVC膜结构材料的耐盐酸性能较好;材料经向撕裂强力大于纬向;材料的顶破试样裂口形式表现为纬纱的断裂.
关键词:
拉伸
,
撕裂
,
顶破
,
膜结构材料
田耘
,
李帅华
,
杨峥
,
柳光祖
,
雷喆
材料热处理学报
研究了具有粗、细两种不同晶粒组织状态的MGH956合金板材室温～1200℃拉伸及1100℃持久性能.采用扫描电镜和金相显微镜对拉伸和持久试样的断口形貌及纵剖面组织进行了检验,对比分析了两种板材不同温度下的强化因素、及变形和断裂模式.结果表明:正是由于强化因素、及变形和断裂模式上的不同,使得细晶板材的拉伸强度在低温高于粗晶板材,在高温则低于粗晶板材,以及细晶板材的持久强度大大低于粗晶板材；但两种板材从室温～ 1200℃的拉伸伸长率并无明显差异.
关键词:
MGH956合金
,
板材
,
拉伸
,
持久
王建涛
,
韩伟
,
骆合力
,
李尚平
材料热处理学报
对MX246A合金进行了两段式均匀化热处理,采用扫描电镜观察了均匀化后的微观组织,测试了铸态和均匀化态MX246A合金在850℃和1100℃下的拉伸性能.结果表明,与铸态相比,均匀化热处理后MX246A合金的1100℃的塑性增加,但850℃的塑性降低.均匀化热处理后在枝晶间和晶界处存在大量被γ’包膜包覆的M6C碳化物;拉伸时,裂纹起源于这些碳化物,并沿碳化物与γ’包膜的界面进行扩展.在850℃时γ’包膜韧性差,碳化物处产生的应力集中无法释放是均匀化后MX246A合金的850℃塑性降低的主要原因.
关键词:
Ni3Al
,
均匀化
,
微观组织
,
拉伸
许平
,
王奡
,
苏智星
钛工业进展
采用厚度为2、4 mm的TA15钛合金板材，通过超塑成形/扩散连接的方法制备TA15钛合金重要承力壁板。经宏观及显微镜观察、超声波无损检测发现，该壁板质量良好。制备与超塑成形/扩散连接壁板的材质、厚度、成形工艺及成形过程完全一致的试验件，考核其拉伸性能、疲劳性能、剪切性能。结果表明，采用该种工艺制造的TA15钛合金壁板的力学性能满足设计要求，同时也指出TA15钛合金超塑成形/扩散连接的工艺参数有待进一步优化。
关键词:
TA15钛合金壁板
,
超塑成形
,
扩散连接
,
拉伸
,
疲劳
,
剪切
孙继鑫
,
徐建刚
,
王轶鹏
兵器材料科学与工程
采用分子动力学方法研究了纳米铜-镍异质金属之间的高温扩散过程，并对退火后得到的扩散模型进行拉伸模拟。结果表明：在相同升温、加压和退火条件下，保温时间越长，扩散模型的过渡层厚度越大，拉伸强度越小；当保温时间为600 ps，扩散模型的拉伸强度为11.62 GPa，达到理想接触铜-镍模型拉伸强度的76%。
关键词:
扩散
,
过渡层
,
拉伸
,
应力-应变
王伟
,
曾卫东
,
冮悦
,
李冬
,
郑友平
,
梁晓波
钛工业进展
B2相区等温锻造的Ti-22Al-25Nb合金棒材940℃固溶后，在760～840℃时效处理，对其显微组织、拉伸及蠕变性能进行研究。结果表明：不同温度时效处理的显微组织均由初生粗板条状O相、二次析出的细板条状O相和B2基体组成，其中二次析出的O相可以通过时效温度来调节。随着时效温度的升高， Ti2 AlNb合金的室温及650℃高温拉伸强度降低而塑性提高；较低的时效温度（760℃）处理可以获得更好的抗蠕变性能。
关键词:
Ti2 AlNb基合金
,
热处理
,
组织演变
,
拉伸
,
蠕变
