Synthesis of full-density nanocrystalline tungsten carbide by reduction of tungstic oxide at room temperature

1996 ◽  
Vol 27 (12) ◽  
pp. 4210-4213 ◽  
Author(s):  
M. Sherif El-Eskandarany ◽  
T. J. Konno ◽  
K. Sumiyama ◽  
K. Suzuki ◽  
M. Omori ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Room Temperature ◽  
Full Density ◽  
Tungstic Oxide

Characteristics of nanophase TiAl produced by inert gas condensation

1992 ◽  
Vol 7 (11) ◽  
pp. 2962-2970 ◽  
Author(s):  
H. Chang ◽  
C.J. Altstetter ◽  
R.S. Averback
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Large Fraction ◽  
Inert Gas ◽  
Full Density ◽  
Indentation Creep ◽  
Small Component ◽  
Grain Sizes ◽  
Transmission Electron ◽  
20 Nm

Nanophase TiAl, with grain sizes in the range of 10–20 nm, was synthesized by magnetron sputtering in an inert gas atmosphere and consolidated, in situ, under vacuum. The properties of the powders and sintered compacts were studied by transmission electron microscopy, scanning electron microscopy, calorimetry, Rutherford backscattering, and x-ray diffraction. Samples compacted at 1.0 GPa at room temperature had a large fraction of amorphous phase, while samples compacted at the same pressure and 250 °C were predominantly the equilibrium γ phase. An enthalpy change of 22 kJ/g-atom was measured during a DSC scan over the temperature range 125–450 °C, which is approximately the range over which crystallization occurs. Nearly full density could be achieved by sintering at 450 °C without significant, concomitant grain growth. The Vickers microhardness of these samples at room temperature and at −30 °C revealed an inverse Hall–Petch relationship at small grain sizes, 10–30 nm, and the usual Hall–Petch behavior at larger grain sizes. A small component of indentation creep was also observed. The maximum hardness is 4 times larger than that of a cast TiAl specimen of the same composition. The Vickers hardness was also observed to decrease rapidly with temperature above 200 °C.

Experimental Assessment of Ball Joints Operation Using Servo-Hydraulic Testing Systems

2015 ◽  
Vol 240 ◽  
pp. 232-237
Author(s):  
Tadeusz Szymczak ◽  
Adam Brodecki ◽  
Andrzej Eminger ◽  
Zbigniew L. Kowalewski ◽  
Dariusz Rudnik
Keyword(s):  
Cyclic Loading ◽  
Tungsten Carbide ◽  
Hydraulic System ◽  
Room Temperature ◽  
Hydraulic Testing ◽  
Ball Joint ◽  
Wear Coefficient ◽  
Experimental Assessment ◽  
Ball Joints ◽  
Sliding Joints

The paper reports experimental results from tests carried out at room temperature on servo-hydraulic system dedicated for examination of the exploitation properties of rocker arms. The ball joint of this element was modified by an application of composite coating such as the tungsten carbide (WC). To apply cyclic loading to rocker arms the griping system was designed and elaborated. Results from tests performed on the composite coated ball joints were compared with data obtained for typical elements. Variations of the following parameters versus time i.e. force, temperature and surface topography of balls were analysed with respect to exploitation properties of the modified ball joints. An increase of the wear coefficient was achieved for sliding joints of the steel ball-steel cups coated by the WC.

Room temperature solution processed tungsten carbide as an efficient hole extraction layer for organic photovoltaics

2014 ◽  
Vol 2 (11) ◽  
pp. 3734-3740 ◽  
Author(s):  
Wei Cui ◽  
Zhongwei Wu ◽  
Changhai Liu ◽  
Mingxing Wu ◽  
Tingli Ma ◽  
...  
Keyword(s):  
Solar Cell ◽  
Tungsten Carbide ◽  
Buffer Layer ◽  
Organic Photovoltaics ◽  
Organic Solar Cell ◽  
High Performance ◽  
Room Temperature ◽  
Solution Processed ◽  
Anode Buffer Layer ◽  
Temperature Solution

We demonstrated tungsten carbide (WC) as an efficient anode buffer layer for a high-performance inverted organic solar cell.

scholarly journals Nano-Indentation Properties of Tungsten Carbide-Cobalt Composites as a Function of Tungsten Carbide Crystal Orientation

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2137
Author(s):  
Renato Pero ◽  
Giovanni Maizza ◽  
Roberto Montanari ◽  
Takahito Ohmura
Keyword(s):  
Tungsten Carbide ◽  
Crystal Orientation ◽  
Advanced Materials ◽  
Full Density ◽  
Micro Hardness ◽  
Electron Backscattered Diffraction ◽  
Nano Indentation ◽  
Mixture Modelling ◽  
Small Set ◽  
The Relationship

Tungsten carbide-cobalt (WC-Co) composites are a class of advanced materials that have unique properties, such as wear resistance, hardness, strength, fracture-toughness and both high temperature and chemical stability. It is well known that the local indentation properties (i.e., nano- and micro-hardness) of the single crystal WC particles dispersed in such composite materials are highly anisotropic. In this paper, the nanoindentation response of the WC grains of a compact, full-density, sintered WC-10Co composite material has been investigated as a function of the crystal orientation. Our nanoindentation survey has shown that the nanohardness was distributed according to a bimodal function. This function was post-processed using the unique features of the finite mixture modelling theory. The combination of electron backscattered diffraction (EBSD) and statistical analysis has made it possible to identify the orientation of the WC crystal and the distinct association of the inherent nanoindentation properties, even for a small set (67) of nanoindentations. The proposed approach has proved to be faster than the already existing ones and just as reliable, and it has confirmed the previous findings concerning the relationship between crystal orientation and indentation properties, but with a significant reduction of the experimental data.

Study on Direct Hot Isostatic Pressing Technology for Superalloy Inconel 625

2011 ◽  
Vol 189-193 ◽  
pp. 2935-2938 ◽  
Author(s):  
Ji Wei Wang ◽  
Qing Song Wei ◽  
Guo Cheng Liu ◽  
Yu Kun He ◽  
Yu Sheng Shi
Keyword(s):  
Room Temperature ◽  
Hot Isostatic Pressing ◽  
Tensile Tests ◽  
Inert Gas ◽  
Inconel 625 ◽  
Full Density ◽  
Fracture Surface Morphology ◽  
Structure And Properties ◽  
Isostatic Pressing ◽  
Pressing Technology

Inert gas atomized (IGA) superalloy Inconel 625 powder was consolidated by hot isostatic pressing (HIPing) directly under the HIPing parameters of 1100°C/110MPa/3h. The structure and properties of the as–HIPed samples were investigated using optical microscopy (OM), scanning electron microscopy (SEM) and tensile tests at room temperature, and its relative density was measured by drainage. The fracture surface morphology of the tensile specimens have been investigated using SEM. The results showed that full density alloy can be obtained under the HIPing parameters of 1100°C/110MPa/3h. Due to the effect of prior particle boundaries (PPBs), the strength of the as-HIPed alloy is comparatively high, but its ductibility is comparatively low.

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