Topic
Carbide
About: Carbide is a research topic. Over the lifetime, 36331 publications have been published within this topic receiving 503586 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, the state of the art in hard coatings for carbide cutting tools including discussion of coating characteristics and applications is presented, as well as a detailed discussion of their application.
Abstract: The majority of carbide cutting tools in use today employ hard coatings because coatings offer proven benefits in terms of tool life and machining performance. Continuing development of the chemical vapor deposition (CVD) coating process, the most widely used technique, has produced complex multilayer coatings tailored for specific applications and workpiece materials. These coatings include alumina layers of different crystal structures, and TiCN layers applied by high- or moderate-temperature (MT-CVD) processes. Over the last decade, coatings applied by physical vapor deposition (PVD) have gained acceptance in applications requiring sharp edges or those featuring interrupted cuts. Originally limited to TiN coatings, the PVD offering now includes TiCN and TiA1N coatings which provide better high-speed performance and increased abrasive wear resistance. In the area of superhard coatings, improvements in deposition processes and coating adhesion have resulted in diamond-coated carbide tools that have begun to play an important role in machining non-ferrous and non-metallic materials. This paper presents the state of the art in hard coatings for carbide cutting tools including discussion of coating characteristics and applications.
199 citations
TL;DR: In this paper, the effects of initial and pozzolanic reactions were investigated to evaluate the stress-strain behavior of a sandy soil improved through the addition of carbide lime and fly ash.
Abstract: Unconfined compression tests, Brazilian tensile tests, and saturated drained triaxial compression tests with local strain measurement were carried out to evaluate the stress-strain behavior of a sandy soil improved through the addition of carbide lime and fly ash. The effects of initial and pozzolanic reactions were investigated. The addition of carbide lime to the soil-fly ash mixture caused short-term changes due to initial reactions, inducing increases in the friction angle, in the cohesive intercept, and in the average modulus. Such improvement might be of fundamental importance to allow site workability and speeding construction purposes. In addition, under the effect of initial reactions, the maximum triaxial stiffness occurred for specimens molded on the dry side of the optimum moisture content, while the maximum strength occurred at the optimum moisture content. After 28 days, pozzolanic reactions magnified brittleness and further increased triaxial peak strength and stiffness; the maximum triaxial strength and stiffness occurred on the dry side of the optimum moisture content.
199 citations
TL;DR: In this article, the thermodynamic stabilities of Cr carbides have been reviewed in the Cr-C, Fe-Cr-V, C, Ni-Cr and W carbides considering the relative stabilities between Cr carbide and V carbide or W carbide.
Abstract: The thermodynamic stabilities of Cr carbides have been reviewed in the Cr-C, Fe-Cr-C, Ni-Cr-C, Fe-Cr-V-C and Fe-Cr-W-C systems considering the relative stabilities between Cr carbides and V carbide or W carbides. A new description of the Cr carbides was made, which can give satisfactory agreement between calculation and experimental data both in the Ni-Cr-C system and the Fe-Cr-V-C system. Taking into consideration the Ni-Cr-C and Fe-Cr-V-C systems, and the relative stabilities between Cr carbides themselves and between Cr carbides and V or W carbide, reassessments were made of the Ni-C, Ni-Cr, Cr-C, Ni-Cr-C and Fe-Cr-C systems. Comparisons between calculation and experimental data are presented for each system reassessed and also for the Fe-Cr-V-C and Fe-Cr-W-C quaternary systems.
198 citations
TL;DR: Density functional theory was employed to investigate the behavior of Mo carbides in the water-gas-shift reaction and it is shown that the O-covered Mo-terminated Mo(2)C(001) (O_Mo-Mo( 2)C) surface displays the lowest WGS activity of all.
Abstract: Density functional theory (DFT) was employed to investigate the behavior of Mo carbides in the water-gas-shift reaction (WGS, CO + H2O → H2 +CO2). The kinetics of the WGS reaction was studied on the surfaces of Mo-terminated Mo2C(001) (Mo−Mo2C), C-terminated Mo2C(001) (C−Mo2C), and Cu(111) as a known active catalyst. Our results show that the WGS activity decreases in a sequence: Cu > C−Mo2C > Mo−Mo2C. The slow kinetics on C−Mo2C and Mo−Mo2C is due to the fact that the C or Mo sites bond oxygen too strongly to allow the facile removal of this species. In fact, due to the strong O−Mo and O−C interactions, the carbide surfaces are likely to be covered by O produced from the H2O dissociation. It is shown that the O-covered Mo-terminated Mo2C(001) (O_Mo−Mo2C) surface displays the lowest WGS activity of all. With the Mo oxide in the surface, O_Mo−Mo2C is too inert to adsorb CO or to dissociate H2O. In contrast, the same amount of O on the C−Mo2C surface (O_C−Mo2C) does not lead to deactivation, but enhances t...
198 citations
TL;DR: In this article, the authors have made advances in understanding radiation damage in SiC at the fundamental level through MD simulations of displacement cascades and showed that SiC composites made with the advanced fibers of Nicalon Type S and the UBE Tyranno SA have excellent thermal conductivity and radiation stability.
198 citations