Carbide

About: Carbide is a research topic. Over the lifetime, 36331 publications have been published within this topic receiving 503586 citations.

Effect of carbide degradation in a Ni-based hardfacing under abrasive and combined impact/abrasive conditions

Abstract: Within this work, the effect of carbide degradation in a WC/W 2 C reinforced Ni-based hardfacing was assessed under abrasive and combined impact/abrasive conditions. In view of the above, a WC/W 2 C reinforced Ni-based hardfacing was deposited by plasma transferred arc (PTA) welding using different welding currents. Microstructure was characterised by quantitative metallography to determine specific structural parameters: mean carbide diameter and carbide area fraction. Scanning electron microscopy (SEM, EDS) and X-ray diffraction (XRD) were also used to characterise carbide dissolution mechanism. Tribological behaviour was determined with a 3-body abrasion test according to ASTM G65 and with a cyclic impact/abrasion test (CIAT). Results showed significant carbide degradation with increasing welding current, resulting in a significant reduced primary carbide content and carbide diameter. Reduced carbide content indicated a significantly wear rate increase under pure 3-body abrasion conditions. Specific wear energy was determined under pure abrasive condition and showed significant dependence on the primary carbide content. However, wear rates under combined impact/abrasion were at constant level due to the reduction of the brittle primary carbide content.

Carbon‐Induced Corrosion of Nickel Anode

Abstract: In high‐temperature solid oxide fuel cells where natural gas is used as a fuel, high‐carbon‐activity environments can be encountered in the anode compartment. Under these conditions, nickel could corrode by a process known as metal dusting. In the present study, metal dusting corrosion of pure nickel is simulated in high‐carbon‐activity environments at temperatures between 350 and 1050°C. The focus of this research is to understand reaction mechanisms by characterizing interfacial processes at the nanometer level. Nickel corrodes by a combination of carbon diffusion and precipitation in the bulk metal and atom migration through surface carbon deposits. The nature of the carbon deposit is important in the overall corrosion process. At lower temperatures closer to about 350°C, nickel forms a carbide. , which is rather stable and does not decompose. © 2000 The Electrochemical Society. All rights reserved.

High coercivity cobalt carbide nanoparticles processed via polyol reaction: A new permanent magnet material

Abstract: Cobalt carbide nanoparticles were processed using polyol reduction chemistry that offers high product yields in a cost effective single-step process Particles are shown to be acicular in morphology and typically assembled as clusters with room temperature coercivities greater than 4 kOe and maximum energy products greater than 20 KJ/m3 Consisting of Co3C and Co2C phases, the ratio of phase volume, particle size, and particle morphology all play important roles in determining permanent magnet properties Further, the acicular particle shape provides an enhancement to the coercivity via dipolar anisotropy energy as well as offering potential for particle alignment in nanocomposite cores While Curie temperatures are near 510K at temperatures approaching 700 K the carbide powders experience an irreversible dissociation to metallic cobalt and carbon thus limiting operational temperatures to near room temperature

Effects of carbon fiber/Al interface on mechanical properties of carbon-fiber-reinforced aluminum-matrix composites

Abstract: Carbon-fiber (CF)-reinforced aluminum-matrix composites were prepared by spreading fibers and squeeze casting. The interface structure of Cf/Al composites was examined using high-resolution transmission electron microscopy (HRTEM) and electron spectroscopy for chemical analysis (ESCA). Aluminum carbide (Al4C3) interfacial reaction products were observed to nucleate heterogeneously from carbon fibers and to grow toward the aluminum matrix in the form of lath-like crystals after heat treatment. The growth of aluminum carbide was anisotropic, since it was faster along the a- and b-axes of the basal plane than along the c-axis. Both the tensile strength and the elongation of composites decline with an increased duration of heat treatment. The results of ESCA revealed that approximately 1 pct of carbide enhanced interface bonding. However, increasing the content of brittle carbides to over 3 pct after heat treatment degraded the mechanical properties of composites.

Ion plating method and product therefrom

Abstract: An ion plating method and product therefrom wherein ions of a metal are implanted into or/and plated onto a substrate to increase the hardness of the surface. After plating, the product can be reacted with carbon, boron, nitrogen or another metal, thereby forming the carbide, boride, nitride or metal compound of the plating metal coating. Hardening of the product by quenching follows which produces a cutting tool of superior qualities.