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Cubic Boron Nitride (cubic + boron_nitride)
Selected AbstractsHot Isostatic Pressing of Cubic Boron Nitride,Tungsten Carbide/Cobalt (cBN,WC/Co) Composites: Effect of cBN Particle Size and Some Processing Parameters on their Microstructure and PropertiesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2007V. Martínez Cubic boron nitride (cBN)-cemented carbide composites have gained attraction over the last few years because of their potential uses as wear parts. The densification behavior of cBN,hard metal composites by glass encapsulation hot isostatic pressing,has been investigated. Composites with different cBN grades (from 0/0.5 to 6/12 ,m particle sizes) and cBN content (up to 50 vol%) were selected for this study. Near-full densification was obtained at temperatures between 1100° and 1200°C, and pressures between 150 and 200 MPa, respectively, while no phase transformation of cBN into the low-hardness hexagonal form has been detected by X-ray diffraction. The addition of cBN to the hard metal base material led to an increase of hardness, a significant increase of fracture toughness (KIC measured by Vickers indentation), and a moderate decrease of mechanical strength (determined by three-point bending). [source] Deposition of Cubic Boron Nitride in a Supersonic Plasma Jet Reactor with Secondary DischargePLASMA PROCESSES AND POLYMERS, Issue S1 2007Jami McLaren Abstract We have deposited cubic boron nitride thin films with a supersonic plasma jet chemical vapor deposition system with bipolar pulsed substrate bias. Deposited films were characterized by Fourier transform infrared spectroscopy, micro-X-ray diffraction, and scanning electron microscopy. The cubic boron nitride content is observed to scale well with the degree of ion bombardment of the substrate and growing film, which is affected most drastically by the substrate bias pulse frequency, and positive and negative duty cycle. The magnitude of the negative substrate bias was also critical in depositing cubic boron nitride, with a threshold voltage of approximately 90 V necessary for cubic boron nitride deposition. [source] Effective Detonation Synthesis of Cubic Boron NitridePROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 6 2009Sergei Abstract Successful realization of detonation-induced h-BN,c-BN phase transition requires that a hydrolysis of BN by water from the detonation products is suppressed. For this two kinds of experiments for synthesis of c-BN were attempted: using benzo-trifuroxan (with no water in products) as an explosive, in 80% yield; and using the cast 50% TNT+50% RDX charges containing 5,25,wt.-% of h-BN powder in order to expend water from the detonation products by a part of BN, and to realize the phase transition in the rest, in 10% yield. [source] Hot Isostatic Pressing of Cubic Boron Nitride,Tungsten Carbide/Cobalt (cBN,WC/Co) Composites: Effect of cBN Particle Size and Some Processing Parameters on their Microstructure and PropertiesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2007V. Martínez Cubic boron nitride (cBN)-cemented carbide composites have gained attraction over the last few years because of their potential uses as wear parts. The densification behavior of cBN,hard metal composites by glass encapsulation hot isostatic pressing,has been investigated. Composites with different cBN grades (from 0/0.5 to 6/12 ,m particle sizes) and cBN content (up to 50 vol%) were selected for this study. Near-full densification was obtained at temperatures between 1100° and 1200°C, and pressures between 150 and 200 MPa, respectively, while no phase transformation of cBN into the low-hardness hexagonal form has been detected by X-ray diffraction. The addition of cBN to the hard metal base material led to an increase of hardness, a significant increase of fracture toughness (KIC measured by Vickers indentation), and a moderate decrease of mechanical strength (determined by three-point bending). [source] Deposition of Cubic Boron Nitride in a Supersonic Plasma Jet Reactor with Secondary DischargePLASMA PROCESSES AND POLYMERS, Issue S1 2007Jami McLaren Abstract We have deposited cubic boron nitride thin films with a supersonic plasma jet chemical vapor deposition system with bipolar pulsed substrate bias. Deposited films were characterized by Fourier transform infrared spectroscopy, micro-X-ray diffraction, and scanning electron microscopy. The cubic boron nitride content is observed to scale well with the degree of ion bombardment of the substrate and growing film, which is affected most drastically by the substrate bias pulse frequency, and positive and negative duty cycle. The magnitude of the negative substrate bias was also critical in depositing cubic boron nitride, with a threshold voltage of approximately 90 V necessary for cubic boron nitride deposition. [source] | ||||||||||