Topic
Boride
About: Boride is a research topic. Over the lifetime, 6189 publications have been published within this topic receiving 69576 citations. The topic is also known as: borides.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, the potential of multicomponent boride, carbide, nitride, and oxide systems as coating materials is discussed in view of their potential as coating material.
Abstract: Multicomponent refractory material systems can provide opportunities for specific materials for wear resistant coatings. The multitude of potential hard coating materials can be subdivided into three groups according to variations in chemical bonding character of the compounds. Many fundamental relations between the position of coating material components in the Periodic Table of the elements and the properties can be used to optimize these material selections. However, restrictions exist because of increasing hardness and strength which primarily decrease toughness and adherence. Multicomponent boride, carbide, nitride, and oxide systems are discussed in view of their potential as coating materials. Additional options for materials selection and optimization arise from the possibility of adjusting specific microstructures in the layers, especially in multilayer and multiphase coatings.
1,020 citations
TL;DR: Initial property assessments show that both the hardness and the oxidation resistance of these high-entropy metal diborides are generally higher/better than the average performances of five individual metal dibiaides made by identical fabrication processing.
Abstract: Seven equimolar, five-component, metal diborides were fabricated via high-energy ball milling and spark plasma sintering. Six of them, including (Hf0.2Zr0.2Ta0.2Nb0.2Ti0.2)B2, (Hf0.2Zr0.2Ta0.2Mo0.2Ti0.2)B2, (Hf0.2Zr0.2Mo0.2Nb0.2Ti0.2)B2, (Hf0.2Mo0.2Ta0.2Nb0.2Ti0.2)B2, (Mo0.2Zr0.2Ta0.2Nb0.2Ti0.2)B2, and (Hf0.2Zr0.2Ta0.2Cr0.2Ti0.2)B2, possess virtually one solid-solution boride phase of the hexagonal AlB2 structure. Revised Hume-Rothery size-difference factors are used to rationalize the formation of high-entropy solid solutions in these metal diborides. Greater than 92% of the theoretical densities have been generally achieved with largely uniform compositions from nanoscale to microscale. Aberration-corrected scanning transmission electron microscopy (AC STEM), with high-angle annular dark-field and annular bright-field (HAADF and ABF) imaging and nanoscale compositional mapping, has been conducted to confirm the formation of 2-D high-entropy metal layers, separated by rigid 2-D boron nets, without any detectable layered segregation along the c-axis. These materials represent a new type of ultra-high temperature ceramics (UHTCs) as well as a new class of high-entropy materials, which not only exemplify the first high-entropy non-oxide ceramics (borides) fabricated but also possess a unique non-cubic (hexagonal) and layered (quasi-2D) high-entropy crystal structure that markedly differs from all those reported in prior studies. Initial property assessments show that both the hardness and the oxidation resistance of these high-entropy metal diborides are generally higher/better than the average performances of five individual metal diborides made by identical fabrication processing.
644 citations
01 Jan 1977
TL;DR: Theoretical interest in the properties of Boron and its properties can be found in this article, where the electronic structure of the Hexaborides and the Diborides is discussed.
Abstract: A. Introduction.- B. Considerations of Theoretical Interest.- I. The Electronic Structure of Boron Compounds.- II. The Nature of the Chemical Bond in Borides.- III. The Electronic Structures of the Hexaborides and the Diborides.- IV. Boron and Aluminum Dodecaboride as the Specific Type of Hopping Conduction Materials.- V. Electron Paramagnetic Resonance (EPR) in Boron Nitride, Boron and Boron Carbide.- VI. Structural Determinants in the Higher Borides.- VII. Crystal Chemistry of Higher Borides.- VIII. Tetragonal Boron-I and Its Derivatives.- IX. Compounds Based on Octahedral B6 Units: Hexaborides and Tetraborides.- X. Crystal Chemistry of Boron and of Some Boron-Rich Phases Preparation of Boron Modifications.- C. Preparations and Properties.- I. Chemical Properties of Boron.- II. Methods of Preparation of Amorphous Boron.- III. Methods of Preparation of ?-Rhombohedral Boron.- IV. Characterization of Localized States in ?-Rhombohedral Boron.- V. Alkali Metal Borides.- VI. Ib and IIb Subgroup Borides.- VII. Borides of the IVb Group.- VIII. Borides of Group VIb Elements.- IX. Transition Metal Borides.- X. Single-Crystal Refractory Borides of Transition Metals.- XI. Properties and Uses of Diborides.- XII. Ternary Metal Borides.- XIII. Rare Earth-Boron Phase Equilibria.- XIV. Metallic Borides: Preparation of Solid Bodies-Sintering Methods and Properties of Solid Bodies.- XV. Magnetic Properties of Borides.- D. Special Applications.- I. Chemical Vapor Deposition of Boron Filament.- II. Boron Carbide Fibers from Carbon Fibers.- III. Boron Nitride Fibers.- IV. Reinforcing Properties of ALB2 Flakes.- V. Amorphous Boron Films.- VI. Boride Coatings.- VII. Nuclear Applications of Boron and the Borides.- VIII. Use of Boron Compounds in Lightweight Armor.
633 citations
TL;DR: In this paper, the wear resistance and high-temperature compression strength of CuCoNiCrAl0.5Fe alloy with various amounts of boron addition were discussed.
Abstract: This study discusses the wear resistance and high-temperature compression strength of CuCoNiCrAl0.5Fe alloy with various amounts of boron addition. Experiments show that within the atomic ratio of boron addition from x=0 to x=1.0 in CuCoNiCrAl0.5FeBx (referred to as B-0 to B-1.0 alloys), the alloys are of fcc structure with boride precipitation. The volume fraction of borides increases with increasing boron addition. The corresponding hardness increases from HV 232 to HV 736. Wear resistance and high-temperature compression strength are significantly enhanced by the formation of boride. The alloys with boride are less tough. The superior wear resistance of B-1.0 alloy, which is even better than SUJ2 wear-resistant steel, indicates that the CuCoNiCrAl0.5FeBx alloys have potential applications as ambient- and high-temperature mold, tool, and structural materials.
493 citations
TL;DR: In this paper, the superconductivity of a quaternary intermetallic, yttrium palladium boride carbide, was observed at 23 K in a multiple-phase bulk sample.
Abstract: COPPER oxide compounds have dominated superconductivity research since 1986 because of their very high transition temperatures (Tcs). In contrast, no new families of high-Tc intermetallic compounds have been discovered since the A15-type Nb3X compounds were first reported in 19531. The intermetallies with highest Jcs have all been based on niobium, with the highest Tcs being 20.7 K for bulk Nb3Ga and 23.2 K for sputtered films of Nb3Ge (refs 2, 3). Here we report the observation of superconductivity at 23 K in a multiple-phase bulk sample of a quaternary intermetallic, yttrium palladium boride carbide. This is higher than any Tc reported previously for a bulk intermetallic compound. Although the materials are not yet single-phase, the superconducting volume fraction is large. We propose that this compound may represent the first of a new family of superconducting intermetallics with relatively high Tcs.
468 citations