|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | EVOLUTION OF MICROSTRUCTURE OF LASER SURFACE ALLOYING OF γ TiAi ALLOY WITH NITROGEN显示文摘Laser surface alloying of γ TiAl alloy with nitrogen was studied under the constant protective nitrogen current (20l /min). The experimental results shown that the surface multi layers formed with experimental parameters could be up to 600μm depth; it consists of TiN,Ti 2AlN,α 2 and γ phases, without AlN, and the irregular coarse continuous “flow” line,dendrite,needle and granular nitrides disperse on the fine dendrite casting α 2 and γ phases substrate. The microstructure and compositions in the nitiding layer were determined and analyzed by SEM and EPMA and the mechanism for the formation of microstructure in the nitriding layer was also discussed. | D.Wen 1) , Q.K.Cai 2) ,C.S. Liu 1) , Y.J. Guo 1) and Y.H.Zhao 1) 1) School of Materials and Metallurgy, Northeastern University, Shenyang 110006,China 2) Shenyang University, Shenyang 110044, China | 1999 | Acta Metallurgica Sinica(English Letters)1999，12，5： | 1 |
| 2 | FORMATION OF GRADIENT COATING OF Fe-BASED ALLOY WITH RARE EARTHS BY PLASMA SURFACING显示文摘A gradient coating of Fe-based alloy was manufactured with rare earths (RE) by plasma surfacing on Q235 steel substrate. The coatings were studied by using X-ray diffraction(XRD), scanning electron microscope(SEM), differential thermal analyzer(DTA), and electron probe micro-analyzer (EPMA). The results show that the phases of the two kinds of coatings(with and without RE) both include α-Fe, Fe7C3, Fe3C, Cr2B, Fe2B and FeB. The microstructure of F314 coating is mainly hypereutectic, the pro-phases Cr7C3 and Cr2B are loose, crassi, spiculate and contain microcracks. The brittleness of the coating is high, and the average hardness is 787 HV. When 0.8wt% RE was added into the F314 alloy, the microstructure varied from hypoeutectic to hypereutectic continuously, The hardness appears as gradient distribution with the highest value of 773 HV, meanwhile, the brittleness decreases significantly. The formation of gradient structure depends on the fallowing factors: (i) the conversion of RE. The addition of RE lowers the elements point and Fe-C eutectic temperature, thus the base metal melting acutely. (ii) the heating of plasma arc. Graded temperature results in directional solidification, thus the gradient structure forms easily. The main reasons for the hardness decrease with RE addition in the alloy are the ratio of hard phase lowering and the hardness of the hard phase decreasing. | L.J.Shang A.Q.Sun J.F.Chen C.M.Zhang Q.K.Cai | 2004 | Acta Metallurgica Sinica(English Letters)2004，17，5： | 1 |
| 3 | THE REINFORCING MECHANISM OF TiB2 IN TiB2/A357 COMPOSITE显示文摘Mechanical properties were tested for in situ TiB2/A357 composite fabricated by LSM (mixed salts reaction) method. Microstructures of as cast and plastic deformed TiB2/A357 were investigated. The results show that there is a low misfit between (200)A1 and (101)TiB2 with [011]Al // [101]TiB2. There is a change from fully dendritic structure of the α-Al of A357 to a rosette-type structure of TiB2/A357. Significant increases in proof stress and Young's modulus can be obtained at low TiB2 additions. There exist dislocation loops around neighboring TiB2 particles with about 0. 1ηm in diameter and dislocation multiplication near TiB2 particles. | B.Yu Y.J.Zhang Z.X.Zhao~ F.X.Zhao: Q.K.Cai C.S.Liu | 2003 | Acta Metallurgica Sinica(English Letters)2003，16，5： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员