C. Q. Wang
,
M. Y. Li and L. Fang (National Key Laboratory of Advanced Welding Production Technology
,
H. I. T.
,
Harbin 150001
,
China)
金属学报(英文版)
The research presented here is focused on the vibration condition of a small volume solder solder ball,which is placed on the surface of a soldering pad and is exerted a pulse modulated continuous wave laser heat source. Finite element method is applied to analyzed the temperature field in the solder ball, and experi- ment is conducted to test the vibration. the results show that,that, the temperature field flucturates with the same frequency as that of the laser pulse, which in turn causes a forced vibration of the same frequency in the liquid solder ball.
关键词:
pulse modulated continuous wave laser
,
null
,
null
Journal of Vacuum Science & Technology a-Vacuum Surfaces and Films
Chromium nitride (CrN) films were deposited on Si wafers by arc ion plating (AIP) at various negative bias voltages and several groups of N-2/Ar gas flux ratios and chamber gas pressures. The authors systematically investigated the influence of negative bias voltage on the synthesis, composition, microstructure, and properties of the AIP CrN films. In this part (Part I), the investigations were mainly focused on the macroparticle distributions and film-growth characteristics. The results showed that macroparticle densities on the film surfaces decreased greatly by applying negative bias voltage, which can be affected by partial pressure of N-2 and Ar gases. From the statistical analysis of the experimental results, they proposed a new hybrid mechanism of ion bombardment and electrical repulsion. Also, the growth of the AIP CrN films was greatly altered by applying negative bias voltage. By increasing the bias voltage, the film surfaces became much smoother and the films evolved from apparent columnar microstructures to an equiaxed microstructure. The impinging high-energy Cr ions accelerated by negative bias voltages were deemed the inherent reason for the evolution of growth characteristics. (c) 2008 American Vacuum Society.
关键词:
chromium nitride films;hybrid coating system;structure zone model;si-n coatings;mechanical-properties;tin films;thin-films;pulse bias;vacuum;evaporation
柯扬船
高分子材料科学与工程
摘要：文中提出了以重质油尤其是渣油分离的芳香分直接聚合成热固性（c—COPNA）或热塑性高聚物材料（t-COPNA）的方法，由此创建了高性能高分子材料原料的新来源与新领域，衍生出新一代耐高温、耐磨损、耐环境及多功能性专用料体系。与从原油裂化制备单体，再聚合成高聚物材料的传统路线相比，重油缩聚高分子材料技术路线具有综合效益高、环保性强而资源更加丰富的突出优点，对于应对能源危机、高分子原料不足的现状，有重大经济社会意义。
关键词:
重质油
,
缩聚
,
热固性高分子材料
,
热塑性高分子材料
,
复合材料
马忠龙
,
杨琤
,
李振花
,
许根慧
催化学报
在常压及650℃下,考察了CaO,SrO,La2O3,ZnO,TiO2,CeO2和MnO2膜上外加电流为16～90 mA时传递物系的甲烷氧化偶联反应结果.结果发现,在n型和p型半导体催化膜上.CC2,C2H4和C2H6的生成速率都随泵氧量的增加而增大,而C2烃选择性随泵氧量的增加而下降,但p型半导体膜上的C2烃选择性比n型半导体膜上的要高;p型半导体膜上C2烃选择性与其电导率大小顺序相一致.增强因子的分析结果表明,在传递体系中,p型半导体膜上增强因子的值小于1,但随泵氧量的增加而存在极大值.在CaO膜上,传递体系比开路体系的C2烃选择性高,且随泵氧量的增加而下降.
关键词:
泵氧
,
半导体催化膜
,
甲烷
,
氧化偶联
,
增强因子
,
传递体系
李海潘道召王芝秀郑子樵
金属学报
doi:10.3724/SP.J.1037.2009.00570
对T6I6时效处理的6061铝合金的拉伸性能、晶间腐蚀性能和电导率进行了测试, 并采用OM和TEM对其组织进行了观察. 结果表明, 6061铝合金经180℃×8 h T6峰值时效后, 虽然强度较高, 但有严重晶间腐蚀倾向;T6I6预时效时间对拉伸性能影响不大, 但中断时效温度和时间对其影响显著.由于较高的中断时效温度和较长的中断时间能获得高密度的晶内析出相和呈球状不连续分布的晶界析出相, 因此, T6I6时效处理后的6061铝合金不仅能保持较高强度, 同时还能显著提高晶间腐蚀抗力. 经180 ℃×2 h+150 ℃×2160 h+180 ℃×8 h T6I6时效, 合金抗拉强度和屈服强度分别为348.5和326.9 MPa, 相对于T6状态, 仅分别下降了2.1%和1.4%,腐蚀类型由T6状态的晶间腐蚀转变为均匀腐蚀, 腐蚀深度约为30 μm.
关键词:
6061铝合金
,
T6I6 temper
,
tensile properties
,
intergranular corrosion
刘文辉
,
杨迅雷
,
张平
,
陈宇强
,
唐思文
材料热处理学报
采用测力仪,表面粗糙度仪、三维表面轮廓仪、透射电镜等对T6和T6I4态7055铝合金的切削加工性能进行研究,分析了时效工艺对7055铝合金加工性能的影响.结果表明,由于T6I4态7055铝合金的析出更加细小密集,T6I4态7055铝合金硬度和强度高于T6态,T6I4态切削表层显微硬度高于T6态;在相同切削条件下,T6I4态的切削力比T6态的切削力小,T6I4态表面粗糙度较T6态低,具有较好的加工质量;在切削热的影响下T6I4态比T6态更易发生回归,因此T6I4态7055铝合金的切削力小于T6态.
关键词:
7055铝合金
,
加工性能
,
时效处理
,
粗糙度
Acta Materialia
Cyclic deformation behavior of Cu-30% Zn single crystals oriented for single slip was studied at constant plastic shear strain amplitudes (gamma(pl)) in the range of 3.8 x 10(-5)-6.4 x 10(-3) in order to understand systematically the fundamental fatigue behavior of low stacking fault energy materials. Results indicate that the cyclic hardening behavior strongly depends on the strain amplitude applied. For low strain amplitudes (gamma(pl) <3 x 10(-4)), cyclic saturation occurred after an initial cyclic hardening stage, but for high strain amplitudes (gamma(pl) greater than or equal to 6.0 x 10(-4)) saturation could not be reached until fatigue failure. The initial cyclic hardening rate (theta(0.2)) was found to decrease with increase in the applied strain amplitude. Slip bands were found to behave very similarly to Luders band appearance at the beginning as well as in the middle stage of cyclic deformation. Particularly, the similarity of the cyclic hardening behavior at low and high strain amplitudes to the work hardening response in stages I and II of tensile deformation of the same alloy has been pointed out. Cyclic stress was further decomposed into two terms, the effective stress and the internal stress, and both were found to increase continuously with cyclic deformation. It has been demonstrated that the activities of secondary slips played an important role in the continuous cyclic hardening at high gamma(pl). A comparison of the present result with previous relevant work on both wavy and planar slip materials has been attempted. The transition of wavy slip mode to planar slip mode of Cu-Al and Cu-Zn alloys has been discussed in terms of the electron-atom ratio and the critical Value of the ratio for such a transition is found to be 1.18-1.19 for both alloys. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.
关键词:
stress-strain response;dislocation-structures;alpha-brass;fatigue;alloys;cu-16;temperature;amplitude
王宝顺林奔张麦仓董建新
金属学报
doi:10.3724/SP.J.1037.2010.00511
研究了G3镍基耐蚀合金管材玻璃润滑热挤压工艺中润滑膜的成膜行为, 建立了润滑膜厚度的理论计算模型. 同时, 针对6000 t卧式挤压机, 结合G3合金热挤压工艺有限元模拟分析, 对热挤压工艺参数和玻璃润滑剂黏度进行了系统的研究. 结果表明, 可以通过玻璃润滑膜厚度及完成一次热挤压所需玻璃垫厚度的理论计算公式优化G3合金管材热挤压工艺参数, 并进一步获得了玻璃润滑剂黏度性质须满足: 玻璃粉的软化温度大约为720 ℃;在720-800 ℃, 玻璃黏温系数在-0.05 ℃-1和-0.04 ℃-1之间;热变形温度1100-1200 ℃区间的黏度为25-200 Pa?s.
关键词:
镍基合金
,
hot extrusion
,
glass lubricant
Journal of Physics and Chemistry of Solids
A new theory of spectral thermal shifts (TS) has been developed. For the first time, by taking into account all the irreducible representations and their components in the electron-phonon interaction (EPI), all the levels and the admixtures of wavefunctions within d(3) electronic configuration, the microscopic expressions for all the parameters in Raman, neighbor-level and optical-branch terms of TS due to EPI have been derived; their values for the R-1, R-2 and ground levels of ruby have been evaluated; the contributions to TS from thermal expansion have also been calculated; and then, the unified calculation of the TS of R-1 and R-2 lines and zero-field splitting (ZFS) for the ground state and the thermal broadenings of R, R' and B line-groups have successfully been accomplished. It is found that the contributions from the second-order term of EPI Hamiltonian H-(2) are dominant in Raman terms of R-1 and R-2 lines; the optical-branch terms play an important role in TS and increase rapidly with temperature and the ones of R-1 and R-2 lines have opposite signs due to the effects of neighbor levels; the neighbor-level terms are very important and it is the admixtures of wavefunctions caused by Coulomb interaction between d electrons and/or trigonal-field and/or spin-orbit interactions that make them nonzero; the contributions to TS from thermal expansion are also important. (C) 2000 Elsevier Science Ltd. All rights reserved.
关键词:
crystal fields;optical properties;phonons;electronic structure;thermal expansion;diamond-anvil cell;entire energy-spectrum;r-line;pressure;measurement;temperature;spectroscopy;calibration;dependence
