A New CBN Crystal for Improved Grinding Performance in Vitrified Bonds

2008 ◽  
Vol 389-390 ◽  
pp. 211-216 ◽  
Author(s):  
Sridhar Kompella ◽  
Kai Zhang ◽  
Rajeev Pakalapati
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Grinding Performance ◽  
Wide Range ◽  
Inconel 718 Superalloy ◽  
Vitrified Bond ◽  
Crystal Synthesis ◽  
End Use ◽  
Cbn Crystal

The use of cubic boron nitride (CBN) over conventional abrasives in ferrous and superalloy grinding has resulted in improved manufacturing throughput and beneficial mechanical properties on workpiece surfaces. However, through the innovative use of crystal synthesis techniques, the grinding performance can be further improved over existing CBN crystals. In this study, such a new CBN crystal is developed, characterized, and its grinding performance is compared to a commercially available CBN crystal. Grinding tests are conducted in AISI M2 steel and Inconel-718 superalloy using a vitrified bond configuration with applicability in a wide range of end-use applications.

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

scholarly journals Mechanical properties of ultra-hard nanocrystalline cubic boron nitride

2019 ◽  
Vol 126 (7) ◽  
pp. 075107 ◽  
Author(s):  
Vladimir L. Solozhenko ◽  
Volodymyr Bushlya ◽  
Jinming Zhou
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Cubic Boron Nitride

Microstructure and Properties of Hot-Pressing Sintered Tungsten Carbide Composites by Adding Cubic Boron Nitride

2015 ◽  
Vol 655 ◽  
pp. 45-48
Author(s):  
Kun Li ◽  
Hai Yan Chen ◽  
Qiu Shuang He ◽  
Li Hua Dong
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Flexural Strength ◽  
Tungsten Carbide ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Cubic Boron Nitride ◽  
Microstructure And Mechanical Properties ◽  
Hot Pressing Sintering ◽  
Sintering Method

(0, 5, 10, 15, 20) vol% CBN-WC/Co composites were consolidated by ball milling and the following hot-pressing sintering method. WC, Co and CBN powders were used as the starting materials. The effects of the CBN content on the density, microstructure and mechanical properties of CBN-WC/Co composites were investigated. The results showed that the CBN content had remarkable influence on the microstructure and mechanical properties of CBN-WC/Co Composites. With the increasing content of CBN, the density decrease, while Vickers hardness and flexural strength increased initially to the maximum values and then decreased at CBN 10 vol%. When 10 vol% CBN-WC/Co powders were hot-pressing sintered at 1350°C and 20MPa for 90 min, an excellent Vickers hardness of 19.8GPa was achieved, combining a flexural strength of 682MPa.

scholarly journals Influence of binder systems on sintering characteristics, microstructures, and mechanical properties of PcBN composites fabricated by SPS

2022 ◽  
Vol 11 (2) ◽  
pp. 321-330
Author(s):  
Shuna Chen ◽  
Hengzhong Fan ◽  
Yunfeng Su ◽  
Wensheng Li ◽  
Jicheng Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Bonding Strength ◽  
Cubic Boron Nitride ◽  
Critical Factor ◽  
High Hardness ◽  
High Porosity ◽  
Plasma Sintering ◽  
Mechanical Performances ◽  
Sintering Characteristics

AbstractCubic boron nitride (cBN) with high hardness, thermal conductivity, wear resistance, and chemical inertness has become the most promising abrasive and machining material. Due to the difficulty of fabricating pure cBN body, generally, some binders are incorporated among cBN particles to prepare polycrystalline cubic boron nitride (PcBN). Hence, the binders play a critical factor to the performances of PcBN composites. In this study, the PcBN composites with three binder systems containing ceramic and metal phases were fabricated by spark plasma sintering (SPS) from 1400 to 1700 °C. The sintering behaviors and mechanical properties of the composites were investigated. Results show that the effect of binder formulas on mechanical properties mainly related to the compactness, mechanical performances, and thermal expansion coefficient of binder phases, which affect the carrying capacity of the composites and the bonding strength between binder phases and cBN particles. The PcBN composite with SiAlON phase as binder presented optimal flexural strength (465±29 MPa) and fracture toughness (5.62±0.37 MPa·m1/2), attributing to the synergistic effect similar to transgranular and intergranular fractures. Meanwhile, the excellent mechanical properties can be maintained a comparable level when the temperature even rises to 800 °C. Due to the weak bonding strength and high porosity, the PcBN composites with Al2O3-ZrO2(3Y) and Al-Ti binder systems exhibited inferior mechanical properties. The possible mechanisms to explain these results were also analyzed.

Heteroepitaxial Growth of Cubic Boron Nitride Single Crystal on Diamond Seed Under High Pressure

1997 ◽  
Vol 472 ◽  
Author(s):  
T. Taniguchi ◽  
S. Yamaoka
Keyword(s):  
High Pressure ◽  
Boron Nitride ◽  
Single Crystal ◽  
Cubic Boron Nitride ◽  
Diamond Surface ◽  
Initial Growth ◽  
Etch Pits ◽  
Step Growth ◽  
Growth Feature ◽  
Cbn Crystal

ABSTRACTSingle crystal cubic boron nitride(cBN) was heteroepitaxially grown on a seed crystal of diamond under static high pressure and high temperature of 5.5GPa and 1600–1700°C, respectively, for 10–100 hour. A temperature gradient method was employed for the crystal growth by using lithium boron nitride as a solvent. Initial growth feature of cBN crystal was found on the diamond seed surface after the growing time of 10 minutes. The nucleation sites of the crystals seem to be near the etch pits on the diamond surface which were introduced by the surface dissolution by the solvent for cBN growth. Two types of growth features, island and step growth were typically shown on the surface. It can be seen that grown crystal appearing as a (111) nitrogen face was exhibited with the step growth feature, while the (11n) face exhibited the island growth feature. Considering the growth process under constant P-T growing condition, growth rate of cBN crystal was significantly small as compared to that of diamond.

scholarly journals Effects of TiAl Alloy as a Binder on Cubic Boron Nitride Composites

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6335
Author(s):  
Yuxi Liu ◽  
Wei Zhang ◽  
Yingbo Peng ◽  
Guojiang Fan ◽  
Bin Liu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Boron Nitride ◽  
Tial Alloy ◽  
Cubic Boron Nitride ◽  
Sintering Process ◽  
Good Oxidation Resistance ◽  
Tial Intermetallics ◽  
High Pressure Sintering ◽  
Sintering Method

Owing to their extreme hardness, cubic boron nitride (cBN) composites are widely used in cutting applications. The performance of cBN composites is closely related to the characteristics of the binder. Therefore, novel binders must be developed to improve the performance of cBN composites. In the present work, TiAl intermetallics were used as binders to fabricate cBN composites by employing a high-temperature and high-pressure sintering method. The phase transformation, sintering reaction mechanism, thermal stability, and mechanical properties of the resultant cBN composites were investigated. It was found that during the sintering process, Ti atoms preferentially reacted with boron nitride particles, whereas Al atoms enriched and transformed into TiAl3 phases and formed cBN/AlN, AlB2/TiN, and TiB2/TiAl3-layered structures eventually. The composites maintained good oxidation resistance at 1200 °C. A decrease in the particle size of the TiAl binder improved the uniformity of particle size distribution and increased the flexural strength of the composites.

Surface Treatment of Cubic Boron Nitride Grains Applied to Vitrified Bond Grinding Tools

2011 ◽  
Vol 675-677 ◽  
pp. 167-170 ◽  
Author(s):  
Zi Cheng Li ◽  
Ai Ju Zhang ◽  
Zhi Hong Li ◽  
Yu Mei Zhu
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Boron Nitride ◽  
Surface Treatment ◽  
Bonding Strength ◽  
Cubic Boron Nitride ◽  
Treatment Technique ◽  
Clean Surface ◽  
Excellent Method ◽  
Vitrified Bond

Cubic boron nitride (cBN) grains treated with hydrochloric acid, nitric acid and sulphuric acid were investigated, respectively. The results indicated that the surface treatment technique with hydrochloric acid was an excellent method for improving the properties of cBN grains. After hydrochloric acid treating, cBN grains with clean surface and satisfied strength were obtained. Moreover, the bonding strength between cBN grains and vitrified bond was increased significantly for application in vitrified bond grinding tools.

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