Z.Y. Lu 1)
,
S.M.An 2)
,
B.H.Cuo 2)
,
W.M.Li 1)
,
Y.Mei
,
Y.L.Xia 2) and J.Xu 2) 1) Department of Mechanical Engineering
,
Yangzhou University
,
Yangzhou 225009
,
China 2) Dalian University of Technology
,
Dalian 116024
,
China
金属学报(英文版)
This study raised a new assisted technique used for chemical vapor deposition (CVD) in which a laser beam irradiated the surface of substrate and simultaneously the plasma surroundings created in the reactive room, but both laser and plasma were at lower energy level in order to perform easily. The chemical vapor deposition reaction could be performed only just using simultaneously above two assisted methods. If not, the reaction could not be performed, too. It is laser plasma assisted chemical vapor deposition (LPCVD). For these reasons, a LPCVD device had been designed and manufactured, and was carried on practical operation. The results indicated that this technique is successful and feasible. Acting on the system of SiH 4 NH 3 N 2 with both CO 2 laser and RF plasma, expectant film of silicon nitride had been obtained on the surface of stainless steel.
关键词:
CVD
,
null
,
null
,
null
W. L. Zhou
,
J. T. Guo
,
R.S. Chen and J. Y Zhou(Institute of Metal Research
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
China)(Department of Materials Engineering
,
Dalian University of Technology
,
Dalian 116024
,
China)
金属学报(英文版)
Our previous investigation examines the soperplastic behavior of an extruded Ni-28.5Al-20.IFe alloy. Its tensile properties were determined at temperature from 1123Kto 1323K and initial strain rates from 1.0{x 10-2s-1 to 1.04x 10-4s-1. A maximumelongation of 233K was obtained at 1123K and a strain rate Oj 5.2x 10-4s-1. Fur-thermore, microstructural features, such a8 decrease in the avempe gmin Bize afier de-formation at 85dC and 98dC the presence oj many dislocationthee gmins adjacentto grains with a high dislocation density, indicate that dynamic recrystallization hasoccuwed as an decient accotnmodation mechanism. SEM examination Of the fracturesample afier saperplastic defOrmation revealS many voids on the hecture sudece. Bycoerelating with the results Oj TEM observation, it is sopested that the soperplasticdejormation in this alloy should be controlled by a gmin boundarp sliding-based mech-anism accommodated by the movement oj dislocation and dynamic recrpstallization.
关键词:
Ni-Al-Fe intermetallics
,
null
Z.Q. Cao
,
L. Y Piao
,
X.G. Zhang
,
Z. Li and J.Z. jin(Research Center of Foundry Engineering
,
Dalian University of Technology
,
Dalian 116024
,
China)
金属学报(英文版)
It is found that the anomalous eutectics can be separated on macroscopic scale by flow caused by electromagnetic stirring, and the separated phase is the leading faceted phase with the solution entmpy over 23J/(mol.K). By using this technology, a new kind of composite pipe ond gear with good abrasive properties are made without adding any reinforced particles. Emphases are paid on the researehes about formation mechanism of seporated eutectic and abrasive property of the composite pipe or gear. The result shows that the entropy of solution controlling the eutectic microstructure is also valid and useful as a criterion of separated eutectic, and the kind and its chemical scope of the off-eutectic used to make composite can be calculated accoofing to this theory.
关键词:
composite pipe or gear
,
null
,
null
,
null
X.L. Xu
,
L. Wang
,
Z. W. Yu and Z.K. Hei(Institute of Metal and Technology
,
Dalian Maritime University
,
Dalian 116024
,
China)
金属学报(英文版)
The cross-sectional microstructure of an ion-nitrided layer on a No.45 steel was studied by transmission electron microscopy (TEM). The results show that the columnar crystals constitute the compound layer. Most of them have the microstructure of alternating ε-Fe2-3N and γ-Fe4N and others are single ε-Fe2-3N phase. There are abnormal strip ferrites between the columnar crystals. The transition layer mainly consists of spherical γ-Fe4N and cementite (Fe3C) particles in the pearlite are dissolved in this layer. In diffusion layer, besides the equilibrium phase γ-Fe4N, there are α -Fe16N2 and the satellite spots around main spots of α-Fe16N2 demonstrate its modulation structure. A metastable ordered cluster zone of the nitropen atoms was found in the division layer.
关键词:
ion nitriding
,
null
,
null
