Oxidation and disproportionation of carbon monoxide over Pd-ZrO2 catalysts prepared from glassy Pd-Zr alloy and by coprecipitation

Author(s):  
S. Gredig ◽  
S. Tagliaferri ◽  
M. Maciejewski ◽  
A. Baiker
Keyword(s):  
Author(s):  
Kenneth S. Vecchio ◽  
David B. Williams

Since the discovery in 1984 by Shechtman et al. of crystals which display apparent five-fold symmetry, extensive effort has been given to establishing a theoretical basis for the existence of icosahedral phases (eg.2.). Several other investigations have been centered on explaining these observations based on twinning of cubic crystals (eg.3.). Recently, the existence of a stable, equilibrium phase T2Al6 Li3Cu) possessing an icosahedral structure has been reported in the Al-Li-Cu system(4-6).In the present study an Al-2.6wt.%Li-l.5wt.%Cu-0.lwt.%Zr alloy was heat treated at 300°C for 100hrs. to produce large T2 precipitates. Convergent Beam Electron Diffraction (CBED) patterns were obtained from two-fold, three-fold, and apparent five-fold axes of T2 particles. Figure 1 shows the five-fold symmetric zero layer CBED pattern obtained from T2 particles.


Author(s):  
D.M. Jiang ◽  
B.D. Hong

Aluminum-lithium alloys have been recently got strong interests especially in the aircraft industry. Compared to conventional high strength aluminum alloys of the 2000 or 7000 series it is anticipated that these alloys offer a 10% increase in the stiffness and a 10% decrease in density, thus making them rather competitive to new up-coming non-metallic materials like carbon fiber reinforced composites.The object of the present paper is to evaluate the inluence of various microstructural features on the monotonic and cyclic deformation and fracture behaviors of Al-Li based alloy. The material used was 8090 alloy. After solution treated and waster quenched, the alloy was underaged (190°Clh), peak-aged (190°C24h) and overaged (150°C4h+230°C16h). The alloy in different aging condition was tensile and fatigue tested, the resultant fractures were observed in SEM. The deformation behavior was studied in TEM.


2000 ◽  
Vol 12 (4) ◽  
pp. 354-357
Author(s):  
David R Smart ◽  
Paul D Mark

Sign in / Sign up

Export Citation Format

Share Document