WAN Lijun Dalian Maritime University
,
Dalian
,
Liaoning
,
China CHEN Baoqing Dalian Institute of Technology
,
Dalian
,
Liaoning
,
China GUO Kexin(K.H.KUO) Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China Institute of Metal and Technology
,
Dalian Maritime University
,
Dalian
,
Liaoning
,
China
金属学报(英文版)
A new phase was found at the interface between Al film and Ni substrate when the time of ion-plating reaches 5 min.It was identified to be body centered tetragonal lattice with the constants a=b=0.588 nm,c=0.480 nm.The variation of microstructure and phases with the ion-plating time were observed.Based on these results,the ion-plating film formation mech- anism has been also discussed.
关键词:
magnetron sputtering
,
null
,
null
,
null
LIANG Yong LI Ruiguo Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
ChinaInstitute of Corrosion and Protection of Metals
,
Aademia Sinica
,
Shenyang
,
110015
,
China
材料科学技术(英文)
Recent advances in laser coating technology including laser cladding,laser surface alloying and laser vapour deposition in China are reviewed in this paper.
关键词:
laser
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null
,
null
,
null
,
null
MA Zongyi YAO Zhongkai Harbin Institute of Technology
,
Harbin
,
China
金属学报(英文版)
The SiC_w/Al composite prepared by squeeze casting has a combination of superior room temperature specific strength and modulus together with excellent thermal properties.The extrusion can make an improvement on the strength and ductility of the composite from 582 MPa as squeeze casted up to 639 MPa,and on the transformation from isotropic to the anisotropic structure.This seems to be explained by the orientation of whiskers and the densification of dislocations in matrix.TEM observation indicates that the stacking fault is the usual planar defect on the SiC_w surface. composite;;SiC whisker;;Al alloy;;microstructure
关键词:
composite
,
null
,
null
,
null
Zhenfang LIAO
,
Shijin ZHANG
材料科学技术(英文)
Electro-hydraulic impulse water-air mixing jet by which the quality of metal materials can be improved is described in this paper. The experimental results proved that the hardness and the micro-hardness of the surface layer of metal materials can be improved with this method, for example, the microhardness of CrWMn can be increased by 35.62 percent.
关键词:
Electro-hydraulic impulse
,
null
,
null
B.W. Wang
,
H. Shen
金属学报(英文版)
Ni-Cr System solar selective thin solid films were prepared by d.c. magnetron reactivesputtering under the atmosphere of O2 and N2. Ni-Cr alloy was chosen as targetmaterial and copper sheets as substrate. Using SEM, Spectrophotometer and Talystepto analyze the relations between the selective characteristic and the structure, theformation and the thickness of the thin films. The aim is to obtain good solar selectivethin films with high absorptance and low emittance, which is applied to flat plate solarheat collectors.
关键词:
solar selective thin film
,
null
,
null
,
null
ZHANG Qunli
,
YAO Jianhua
,
Jyoti Mazumder
钢铁研究学报(英文版)
Multilayer of laser direct metal deposition (DMD) was prepared by depositing a gas atomized prealloyed powder with a composition close to Inconel 718 alloy on Inconel 718 high temperature alloy substrate. The effects of the DMD parameters on the buildup rate and the structure of the deposited layer were studied. The laser DMD sample was further processed by a solution treatment. The microstructure and property of the laser DMD zone before and after heat treatment were investigated as well. The results show that the laser parameters of actual laser power of 650 W, scanning speed of 58 mm/s, beam diameter of 1 mm, powder feed rate of 645 g/min, with a corresponding specific energy of 90-130 J/mm2, can be recommended as optimum parameters for high buildup rate of Inconel 718 alloy. Under the condition of optimized parameters, a directional solidification microstructure was obtained and the average distance between the columnar crystals was 5-10 μm. The microcomposition segregation was found between the columnar crystal trunk and columnar crystal. The elements of Nb, Mo, Ti concentrated in the columnar crystal trunk. After the heat treatment, the segregation was greatly minimized, and the segregation ratios were close to 1. The hardness of the laser deposited layer did not show obvious difference along the height of the layer either for the asdeposited layer or for the heat treated layer. However, the microhardness of the laser DMD zone after heat treatment was obviously higher than that after the asdeposited treatment. During the heat treatment process, some Nb and Morich phases precipitated and strengthened DMD layer.
关键词:
laser DMD; Inconel 718 alloy; composition segregation; microstructure; hardness