|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | FRACTURE MECHANISM AND MICROMECHANICAL ANALYSIS OF POLYSYNTHETICALLY TWINNED CRYSTALS OF γTiAl ALLOYS显示文摘The fracture behavior and mechanism of PST crystals of a Ti 49%(mole fraction)Al alloy have been studied by using in situ straining and micromechanical calculation. The three dimensional micromechanical model representing the structure of PST crystal has been built, and the stress distribution ahead of the sharp and blunt crack tips either parallel to lamellar interface or perpendicular to the lamellae has been calculated by using finite element method based on linear elasticity of PST crystals. The experimental results show that the fracture behaviors and mechanisms are strongly dependent on the angle of loading axis to the lamellae. The calculation indicates that nucleation and propagation of microcrack along the interfaces are controlled by the normal stress and translamellar microcrack is controlled by shear stress ahead of crack tip. | Y.G.Zhang, Y.H.Lu, G.K.Hu * and C.Q.Chen Department of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics Unversity, Beijing 100083,China * Department of Applied Mechanics, Beijing Institute of Technology, | 1999 | 中国有色金属学会会刊:英文版1999，9，S1： | 3 |
| 2 | SYNTHESIS AND THERMAL STABILITY OF NANOCOMPOSITE nc-TiN/a-TiB_2 THIN FILMS显示文摘Several nc-TiN/a-TiB2 thin films comprised of nanocrystalline (nc-) TiN and amor phous (a-) TiB2 phases were deposited on Si(100) at room temperature by reactive unbalanced dc magnetron sputtering, followed by vacuum annealed at 400, 600, 80 0 and 1000℃ for 1h, respectively. Effects of B content on microstructure, mecha nical behaviors and thermal microstructure stability have been investigated by X -ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and nanoindentation measurements. The results indicated that B addition greatly affected both microstructure and mechanical behavior of nc-Ti N/a-TiB2 thin films. With increasing B content the grain size decreased. A maxim um hardness value of about 33GPa was obtained at B content of about 19at.%. The improved mechanical properties of nc-TiN/a-TiB2 films with the addition of B int o TiN were attributed to their densified microstructure with development of fine grain size. Only addition of sufficient B could restrain grain growth during an nealing. High B content resulted in high microstructure stability. The crystalli zation of amorphous matrix occurred at about 800℃, forming TiB or TiB2 crystall ite, depending on B content. Before that no change in bonding configuration was found. | Y.H.Lu Z.F.Zhou P.Sit Y.G.Shen K.Y.Li H.Chen | 2005 | Acta Metallurgica Sinica(English Letters)2005，18，3： | 1 |
| 3 | COMPOSITION EFFECT ON DRY SLIDING WEAR BEHAVIORS OF Ti-B-N THIN FILMS显示文摘Friction and sliding wear behaviour of Ti-B-N coatings against AISI440C steel ball and WC-6wt%Co ball were studied by using pin-on-disk tribometer along with microstructure characterization using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It is shown that the wear resistance of film depended on the wear mechanism. In the case of AISI440C steel, adhesive wear were pre-dominant and the wear rate increased sharply to a maximum when N content reach ~38at. %. This might be related to the change of film microstructure and phase configuration, so the least adhesive transfer of tribo-film was observed. If WC-6wt% Co ball was used, less deformation wear debris was observed, this was responsible for the rise of wear rate. Despite of different wear modes, friction coefficients in both cases were found to depend mainly on the formation and the amount of h-BN phase. Elemental analysis by energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) revealed that oxygen participated in the wear behavior by reacting with films to form the debris comprised of various types of Ti oxide including TiO, TiO2 and Ti2O3 ,which increased wear resistance. | P.Sit Y.H.Lu H.Chen Z.F.Zhou Y.G.Shen K.Y.Li | 2005 | Acta Metallurgica Sinica(English Letters)2005，18，3： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员