1. |
- Gong, Karin Anne Xia, 1965, et al.
(author)
-
Ni3Al-based Intermetallic Alloys as A New Type of High-Temperature and Wear-Resistant Materials
- 2007
-
In: Journal of Iron and Steel Research International. - 1006-706X. ; 14:5, Suppl. 1, s. 21-25
-
Journal article (peer-reviewed)abstract
- Some intermetallics as high-temperature wear-resistant materials attracted attention of material researchers due to their intrinsic long-range ordered crystalline structures with strong oriented atomic bonding. In the group, Ni3Al-based intermetallic alloys are especially interesting for certain tribological applications. In this work, the wear-behaviour of an existed Ni3Al-based alloy, 77.7Ni-9.8Al-11.5Fe-0.5Mn-0.5Ti-0.1B in weight percentage, and its composites reinforced by Cr3C2-particles were studied, and related to their microstructures. HIPing and casting processes were applied for preparing the materials. Wear-rate of the testing materials under different loads and their scuffing resistance were measured by Pin-on-Disk method. The tested materials were analysed by SEM, EDS, and XRD techniques. The results revealed that the single phase Ni3Al-based alloy showed a reasonable wear-resistance, compared to a duplex microstructure. And, the investigation also indicated that the hard Cr-carbide played a positive role on tribological intermetallics, especially for reducing the wear-rate.
|
|
2. |
- He, J., et al.
(author)
-
Switching of a photochromic molecule on gold electrodes: single-molecule measurements
- 2005
-
In: Nanotechnology. - : IOP Publishing. - 1361-6528 .- 0957-4484. ; 16:6, s. 695-702
-
Journal article (peer-reviewed)abstract
- We have studied the electronic changes caused by light-induced isomerization of a photochromic molecule between an open state (that absorbs in the UV to become closed) and a closed state (that absorbs in the visible to become open). Data obtained using a newly developed repetitive break junction method are interpreted in terms of single-molecule resistances of 526 +/- 90 M Omega in the open form and 4 +/- 1 M Omega in the closed form when the molecule is bound between two gold contacts via dithiol linkages. The corresponding ratio of open to closed resistance is in close agreement with the results of ab initio calculations, though the measured resistances are about half of the calculated values. Optical spectroscopy indicates that the photoisomerization occurs in both directions on small gold particles, evaporated thin gold films, and in the break junction experiments.
|
|