Rh-Mn/tungsten carbides for direct synthesis of mixed alcohols from syngas: Effects of tungsten carbide phases

2018 ◽  
Vol 255 ◽  
pp. 44-52 ◽  
Author(s):  
Ba Da Won ◽  
Min Hye Jeong ◽  
Myeong Hun Kim ◽  
Chan-Hwa Chung ◽  
Dong Ju Moon ◽  
...  
RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 101535-101543 ◽  
Author(s):  
Ba Da Won ◽  
Hyeongwon Ham ◽  
Jae Min Cho ◽  
Jong-Bae Lee ◽  
Chul-Ung Kim ◽  
...  

Roles of Mn promoter on Rh-impregnated mesoporous tungsten carbides (WxC) have been investigated for direct synthesis of mixed alcohols by CO hydrogenation of syngas.


2007 ◽  
Vol 111 (42) ◽  
pp. 15173-15184 ◽  
Author(s):  
Linhua Hu ◽  
Shengfu Ji ◽  
Zheng Jiang ◽  
Huanling Song ◽  
Pingyi Wu ◽  
...  

2009 ◽  
Vol 76-78 ◽  
pp. 609-612 ◽  
Author(s):  
H.Q. Sun ◽  
Rudy Irwan ◽  
Han Huang ◽  
Gwidon W. Stachowiak

The effect of microstructure of cemented tungsten carbide materials on their mechanical properties and wear characteristics was investigated using nanoindentation and nanoscratch methods. The results indicated that the variation in grain size insignificantly affected the hardness, elastic modulus and friction coefficient of the work materials, but considerably influenced their removal rates. The carbide with coarser grains exhibited a much higher removal rate was obtained during scratching.


Wood Research ◽  
2021 ◽  
Vol 66 (4) ◽  
pp. 606-620
Author(s):  
PUTRA PANGESTU KIDUNG TIRTAYASA ◽  
WAYAN DARMAWAN ◽  
DODI NANDIKA ◽  
IMAM WAHYUDI ◽  
LUMONGGA DUMASARI ◽  
...  

The purpose of this research was to analyze the performance (wear resistance, surface roughness, chip formation, and noise level) of AlCrN, TiN, and TiAlN coated tungsten carbides in cutting composite boards. The composite boards of wood plastic composite, laminated veneer lumber, andorientedstrand board were cut by the coated tungsten carbide tools in a computer numerical control router. The results show that the differences in structure among the composite boards resulted in the difference in clearance wear, chip formation, surface roughness, and noise level phenomenon. The abrasive materials in wood plastic composite generated the highest clearance wear on the coated carbide tools tested. TiAlN coated carbide tool provided better wear resistance, smoother composite boards surfaces, and lower noise levels.


Author(s):  
A. E. Zatoka ◽  
D. V. Drobot ◽  
S. P. Merchev ◽  
S. V. Nevezhin ◽  
A. S. Gerasimov ◽  
...  

It was investigated the influence of technological parameters of laser cladding on the thickness of the carbide composite coatings with similar composition and properties of matrix and different types of reinforcing inclusions (spherical tungsten carbides (WC) and recycled carbides). Special attention is paid to physical-mechanical and service properties of the composites such as hardness and resistance to abrasive wear. It is established that the thickness of the carbide composite coatings increases with increasing laser power and flow rate of the carrier gas, and with decreasing speed of the laser and the step of cladding. The study showed that at the addition of 50 wt.% WC matrix has smaller hardness values 540-560 HV, which allows to obtain the structure of the carbide composite coatings without cracks. At the same time, at addition of 80 wt.% WC matrix has higher hardness 670 HV, which does not provide the structure without cracks. Resistance of composites NiCrBSiC-WC to cracking, as well as their wear resistance, increases with increasing content of tungsten carbide. The wear resistance of the coatings received from powder Technicord 655-SL, with a reinforcement by recycled carbide, comparable to that for coatings from spherical tungsten carbide Tekmat WC-125. Coatings NiCrBSiCWC, obtained by laser cladding, are used to increase the service life of the equipment telemetering systems, in particular, it is possible to prevent of abrasion and provide of increasing the service life of the contact pads of the equipment for measurement while drilling.


Author(s):  
Aleksandr Gorlenko ◽  
Sergey Davydov ◽  
Mikhail Shevtsov

The use of the technology of combined electromechanical processing, consisting of a high-temperature plastic deformation mode, when tungsten carbide powder is implanted into the surface of carbon steel, and a high-temperature thermal hardening mode, during which tungsten carbides are partially dissolved in the austenite of steel up to the limit of its saturation with tungsten, provided a gradient wear-resistant three-layer highly dispersed structure as a result of the decomposition of supercooled austenite oversaturated with tungsten. The results of tribotechnical tests of cylindrical specimens by the normalized method are presented.


2012 ◽  
Vol 24 (45) ◽  
pp. 455704 ◽  
Author(s):  
H M Tütüncü ◽  
S Baǧcı ◽  
G P Srivastava ◽  
A Akbulut

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