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
2015 ◽  
Vol 655 ◽  
pp. 45-48
Author(s):  
Kun Li ◽  
Hai Yan Chen ◽  
Qiu Shuang He ◽  
Li Hua Dong

(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.


2022 ◽  
Vol 11 (2) ◽  
pp. 321-330
Author(s):  
Shuna Chen ◽  
Hengzhong Fan ◽  
Yunfeng Su ◽  
Wensheng Li ◽  
Jicheng Li ◽  
...  

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.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6335
Author(s):  
Yuxi Liu ◽  
Wei Zhang ◽  
Yingbo Peng ◽  
Guojiang Fan ◽  
Bin Liu

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.


2019 ◽  
Vol 39 (16) ◽  
pp. 5181-5189
Author(s):  
H. Besharatloo ◽  
S. Gordon ◽  
T. Rodriguez-Suarez ◽  
A. Can ◽  
W.C. Oliver ◽  
...  

2019 ◽  
Vol 799 ◽  
pp. 257-262
Author(s):  
Tatevik Minasyan ◽  
Le Liu ◽  
Sofiya Aydinyan ◽  
Maksim Antonov ◽  
Irina Hussainova

Titanium has been evaluated in a broad range of aerospace, biomedical and sports equipment applications due to its unique combination of high mechanical strength, light weight and good biocompatibility. However, Ti implants are often subject to wear in specific areas. Therefore, the improvement of mechanical properties, such as hardness, wear resistance, bearing capability of implants is a key point to broaden the application fields of titanium. Cubic boron nitride (cBN) is a well-known superhard material possessing high chemical stability and biocompatibility. However, cBN suffers from poor machinability and sinterability. Attempts to process boron nitride by laser treatment into intricate shapes are extremely difficult, expensive and time-consuming tasks squeezing its applicability. In this work, manufacturing of Ti/cBN cellular structures and solid parts of high strength and good wear resistance by selective laser melting was performed. In Ti/cBN composite powder, the boron nitride provides the excellent mechanical properties, and titanium promotes the laser absorption improving the process of densification. The parametric study of consolidation process has been performed and the microstructural features along with mechanical properties are examined.


2017 ◽  
Vol 728 ◽  
pp. 836-843 ◽  
Author(s):  
Bilal Anjum Ahmed ◽  
Abbas Saeed Hakeem ◽  
Tahar Laoui ◽  
Raja Muhammad Awais Khan ◽  
Moath Mohammad Al Malki ◽  
...  

2008 ◽  
Vol 389-390 ◽  
pp. 211-216 ◽  
Author(s):  
Sridhar Kompella ◽  
Kai Zhang ◽  
Rajeev Pakalapati

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.


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