Structure engineering of PtCu3/C catalyst from disordered to ordered intermetallic compound with heat-treatment for the methanol electrooxidation reaction

1977 ◽

Vol 35 ◽

pp. 272-273

Author(s):

S. M. L. Sastry

Keyword(s):

Intermetallic Compound ◽

Strain Rate ◽

Tensile Creep ◽

Slip Systems ◽

Slip Vector ◽

Superlattice Structure ◽

Slip Activity ◽

Dislocation Arrangement ◽

Ordered Intermetallic ◽

Tangled Dislocation

Ti3Al is an ordered intermetallic compound having the DO19-type superlattice structure. The compound exhibits very limited ductility in tension below 700°C because of a pronounced planarity of slip and the absence of a sufficient number of independent slip systems. Significant differences in slip behavior in the compound as a result of differences in strain rate and mode of deformation are reported here.Figure 1 is a comparison of dislocation substructures in polycrystalline Ti3Al specimens deformed in tension, creep, and fatigue. Slip activity on both the basal and prism planes is observed for each mode of deformation. The dominant slip vector in unidirectional deformation is the a-type (b) = <1120>) (Fig. la). The dislocations are straight, occur for the most part in a screw orientation, and are arranged in planar bands. In contrast, the dislocation distribution in specimens crept at 700°C (Fig. lb) is characterized by a much reduced planarity of slip, a tangled dislocation arrangement instead of planar bands, and an increased incidence of nonbasal slip vectors.

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Heat Treatment-Induced Microstructure and Property Evolution of Mg/Al Intermetallic Compound Coatings Prepared by Al Electrodeposition on Mg Alloy from Molten Salt Electrolytes

Materials ◽

10.3390/ma14061407 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1407

Author(s):

Tianyu Yao ◽

Kui Wang ◽

Haiyan Yang ◽

Haiyan Jiang ◽

Jie Wei ◽

...

Keyword(s):

Heat Treatment ◽

Intermetallic Compound ◽

Intermetallic Compounds ◽

Mg Alloy ◽

X Ray Diffraction ◽

Electron Backscattered Diffraction ◽

Alloy Matrix ◽

Comprehensive Properties ◽

Compound Coatings ◽

Compound Coating

A method of forming an Mg/Al intermetallic compound coating enriched with Mg17Al12 and Mg2Al3 was developed by heat treatment of electrodeposition Al coatings on Mg alloy at 350 °C. The composition of the Mg/Al intermetallic compounds could be tuned by changing the thickness of the Zn immersion layer. The morphology and composition of the Mg/Al intermetallic compound coatings were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and electron backscattered diffraction (EBSD). Nanomechanical properties were investigated via nano-hardness (nHV) and the elastic modulus (EIT), and the corrosion behavior was studied through hydrogen evolution and potentiodynamic (PD) polarization. The compact and uniform Al coating was electrodeposited on the Zn-immersed AZ91D substrate. After heat treatment, Mg2Al3 and Mg17Al12 phases formed, and as the thickness of the Zn layer increased from 0.2 to 1.8 μm, the ratio of Mg2Al3 and Mg17Al12 varied from 1:1 to 4:1. The nano-hardness increased to 2.4 ± 0.5 GPa and further improved to 3.5 ± 0.1 GPa. The Mg/Al intermetallic compound coating exhibited excellent corrosion resistance and had a prominent effect on the protection of the Mg alloy matrix. The control over the ratio of intermetallic compounds by varying the thickness of the Zn immersion layer can be an effective approach to achieve the optimal comprehensive performance. As the Zn immersion time was 4 min, the obtained intermetallic compounds had relatively excellent comprehensive properties.

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Formation of Fe-Al Intermetallic Compound Film on Hot Work Tool Steel by Shot Lining and Heat Treatment

PRICM ◽

10.1002/9781118792148.ch252 ◽

2013 ◽

pp. 2035-2042

Author(s):

Yasunori Harada ◽

Makoto Ishida ◽

Katsuhiko Takahashi ◽

Yoshinori Sakamoto

Keyword(s):

Heat Treatment ◽

Intermetallic Compound ◽

Tool Steel ◽

Hot Work Tool Steel

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In situ investigations on the oxidation of the ordered intermetallic compound Co0.6Ga0.4

Solid State Ionics ◽

10.1016/s0167-2738(00)00558-0 ◽

2000 ◽

Vol 136-137 (1-2) ◽

pp. 971-977 ◽

Cited By ~ 2

Author(s):

U Koops

Keyword(s):

Intermetallic Compound ◽

Ordered Intermetallic

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Synthesis of Fe-rich Fe–Al nanocrystalline solid solutions using ball milling

Journal of Materials Research ◽

10.1557/jmr.1999.0238 ◽

1999 ◽

Vol 14 (5) ◽

pp. 1760-1770 ◽

Cited By ~ 18

Author(s):

H. G. Jiang ◽

H. M. Hu ◽

E. J. Lavernia

Keyword(s):

Heat Treatment ◽

Activation Energy ◽

Thermal Stability ◽

Intermetallic Compound ◽

Ball Milling ◽

Microstructural Evolution ◽

Solid Solutions ◽

Al Alloys ◽

Time Intervals ◽

Thermal Stability Of

The synthesis of nanocrystalline Fe, Fe–4 wt% Al, and Fe–10 wt% Al solid solutions by SPEX ball milling has been studied. The microstructural evolution during ball milling, as well as subsequent heat treatment, has been characterized. The results demonstrate that ball milling promotes the formation of αFe–4 wt% Al and αFe–10 wt% Al solid solutions by reducing the activation energy of these alloys and generating thermal energy during this process. For Fe–10 wt% Al powders milled for various time intervals up to approximately 20 min, the FeAl intermetallic compound is formed. For alloys annealed at temperatures ranging from 600 to 1000 °C, the addition of 10 wt% Al to Fe significantly enhances the thermal stability of the nanocrystalline Fe–Al alloys. Interestingly, the addition of Al within the range of 4–10 wt% seems to have little effect on the thermal stability of these alloys annealed under the same conditions. Also, the thermal stability improves for alloys milled in air as opposed to those processed using Ar.

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Research on Properties of Amorphous Cr-C Alloy Coating in Crystallization Evolution

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.184-185.1175 ◽

2012 ◽

Vol 184-185 ◽

pp. 1175-1180

Author(s):

Guo Liang Li ◽

Xiao Hua Jie ◽

Bi Xue Yang

Keyword(s):

Heat Treatment ◽

Corrosion Resistance ◽

Intermetallic Compound ◽

Adhesion Force ◽

Alloy Coating ◽

Treatment Temperature ◽

X Ray Diffraction ◽

X Ray ◽

Proper Values ◽

Peak Value

Amorphous Cr–C alloy coating was prepared by electrodepositing. The microhardness of the coating was tested after annealing from 100°C to 800°C and the crystallization evolution was studied by the analysis of X-ray diffraction (XRD) and differential scanning caborimetry (DSC). The results showed that the crystallization evolution of the coating began at 300°C and finished around 450°C, and intermetallic compound Cr7C3and Cr23C6appeared when heat treatment temperature reached around 600°C. The microhardness, corrosion resistance as well as the adhesion of the coating all increased first with the temperature and then dropped until it attained the proper values. The microhardness reached the maximum of 1610HV0.025at 600°C. While the corrosion resistance and the adhesion force attained the peak value at about 400°C.

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