Hybrid forming mechanism of patternless casting and laser cladding

2019 ◽  
Vol 14 (4) ◽  
pp. 393-401
Author(s):  
Zhongde Shan ◽  
Fuzhen Sun ◽  
Yang Liu
2010 ◽  
Vol 450 ◽  
pp. 214-218 ◽  
Author(s):  
Li Xia Ying ◽  
Li Dong Jiang ◽  
Fan Kai Kong ◽  
En Xia Yang

In order to improve the antiwear and antifriction performances of tribological metal surfaces for the extreme conditions, the composite coating has been fabricated on metal surfaces by the technology of laser cladding. In the experiment, Ni-based alloy, TiC and Nickel-coated graphite are used as the main ingredients of composite. The cross-sectional macrographs, microstructure, compositions, microhardness, tribological properties and the forming mechanism of the coating was tested and analyzed. Results show that laser cladding Ni60A/TiC/Nickel-coated graphite composite can obtain excellent coating with fully compact and uniform microstructure, and good interface with the substrate. The microhardness of the clad coating is over HV1000, which is five times higher than that of the steel substrate. The friction coefficient is reduced to about 0.4-0.5 in comparison with that of the steel substrate (about 0.7-0.8). At the same time, the wear resistance of the clad coating is also improved greatly.


Author(s):  
Uwe Lücken ◽  
Michael Felsmann ◽  
Wim M. Busing ◽  
Frank de Jong

A new microscope for the study of life science specimen has been developed. Special attention has been given to the problems of unstained samples, cryo-specimens and x-ray analysis at low concentrations.A new objective lens with a Cs of 6.2 mm and a focal length of 5.9 mm for high-contrast imaging has been developed. The contrast of a TWIN lens (f = 2.8 mm, Cs = 2 mm) and the BioTWTN are compared at the level of mean and SD of slow scan CCD images. Figure 1a shows 500 +/- 150 and Fig. 1b only 500 +/- 40 counts/pixel. The contrast-forming mechanism for amplitude contrast is dependent on the wavelength, the objective aperture and the focal length. For similar image conditions (same voltage, same objective aperture) the BioTWIN shows more than double the contrast of the TWIN lens. For phasecontrast specimens (like thin frozen-hydrated films) the contrast at Scherzer focus is approximately proportional to the √ Cs.


Author(s):  
Yang Xi-Chen ◽  
Li Hui-Shan ◽  
Wang Yun-Shan ◽  
Ma Bing ◽  
Yi Ying-Hui

Author(s):  
Xi-Chen Yang ◽  
Yu-He Yan ◽  
Men-Lin Zhong ◽  
Jiang-Ting Zhang ◽  
Nai-Kun Zhang ◽  
...  
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