The Formation of Oxycarbides During the Oxide Treatment of Cemented Carbide Tools

1974 ◽  
Vol 96 (4) ◽  
pp. 1268-1271
Author(s):  
S. K. Naik ◽  
N. P. Suh

Reactions between oxides and carbides were investigated in order to establish enhancement mechanisms occurring during the oxide treatment of cemented carbide tools. TiO powder was compacted around solid WC and TiC specimens, which were then heated to 1400 deg C in a vacuum of 10−4 to 10−5 torr. The reactions of Al2O3 with these carbides was similarly investigated. X-ray diffraction analysis show that oxycarbides formed on the carbide surface during the oxide treatment. Discussions are given with regard to how these oxycarbides may enhance the metal cutting properties of cemented carbide tools.

1975 ◽  
Vol 97 (1) ◽  
pp. 112-118 ◽  
Author(s):  
S. K. Naik ◽  
N. P. Suh

The mechanisms responsible for enhancement of the metal cutting properties of cemented carbide tools during oxide treatments are investigated. The reaction of individual phases present in cemented carbide tools with various oxides was analyzed experimentally under temperature-pressure conditions previously employed for the oxide treatment. The change in the surface structure and the formation of new phases were determined by means of X-ray diffraction, oxidation experiments, and thermodynamic analyses. The experimental results show that during the oxide treatment such carbides as TiC and ZrC, which are chemically more stable than WC, form on the surface of WC. It was also found that a small percentage of oxides mixed in the eutectic phase of Co-WC stabilizes the eutectic phase, thus preventing its adhesion to a solid piece of oxides.


1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.


2008 ◽  
Vol 73 (8-9) ◽  
pp. 1205-1221 ◽  
Author(s):  
Jiří Zedník ◽  
Jan Sedláček ◽  
Jan Svoboda ◽  
Jiří Vohlídal ◽  
Dmitrij Bondarev ◽  
...  

Dinuclear rhodium(I) η2:η2-cycloocta-1,5-diene (series a) and η2:η2-norborna-2,5-diene (series b) complexes with μ-RCOO- ligands, where R is linear C21H43 (complexes 1a, 1b), CH2CMe3 (2a, 2b), 1-adamantyl (3a, 3b) and benzyl (4a, 4b), have been prepared and characterized by spectroscopic methods. Structures of complexes 2b, 3a and 4a were determined by X-ray diffraction analysis. Complexes prepared show low to moderate catalytic activity in polymerization of phenylacetylene in THF giving high-cis-transoid polymers, but they show only oligomerization activity in dichloromethane.


1987 ◽  
Vol 262 (10) ◽  
pp. 4917-4921 ◽  
Author(s):  
A. Joachimiak ◽  
R.Q. Marmorstein ◽  
R.W. Schevitz ◽  
W. Mandecki ◽  
J.L. Fox ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document