scholarly journals Improvement of Vickers hardness measurement on SWNT/Al2O3 composites consolidated by spark plasma sintering

2014 ◽  
Vol 34 (15) ◽  
pp. 3801-3809 ◽  
Author(s):  
A. Morales–Rodríguez ◽  
A. Gallardo–López ◽  
A. Fernández–Serrano ◽  
R. Poyato ◽  
A. Muñoz ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
Hardness Measurement ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Vickers Hardness Measurement

scholarly journals Refractory High-Entropy HfTaTiNbZr-Based Alloys by Combined Use of Ball Milling and Spark Plasma Sintering: Effect of Milling Intensity

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1268 ◽  
Author(s):  
Natalia Shkodich ◽  
Alexey Sedegov ◽  
Kirill Kuskov ◽  
Sergey Busurin ◽  
Yury Scheck ◽  
...  
Keyword(s):  
Solid Solution ◽  
Ball Milling ◽  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
High Energy ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Energy Ball

For the first time, a powder of refractory body-centered cubic (bcc) HfTaTiNbZr-based high-entropy alloy (RHEA) was prepared by short-term (90 min) high-energy ball milling (HEBM) followed by spark plasma sintering (SPS) at 1300 °C for 10 min and the resultant bulk material was characterized by XRD and SEM/EDX. The material showed ultra-high Vickers hardness (10.7 GPa) and a density of 9.87 ± 0.18 g/cm³ (98.7%). Our alloy was found to consist of HfZrTiTaNb-based solid solution with bcc structure as a main phase, a hexagonal closest packed (hcp) Hf/Zr-based solid solution, and Me2Fe phases (Me = Hf, Zr) as minor admixtures. Principal elements of the HEA phase were uniformly distributed over the bulk of HfTaTiNbZr-based alloy. Similar alloys synthesized without milling or in the case of low-energy ball milling (LEBM, 10 h) consisted of a bcc HEA and a Hf/Zr-rich hcp solid solution; in this case, the Vickers hardness of such alloys was found to have a value of 6.4 GPa and 5.8 GPa, respectively.

Preparation of β SiAlON-cBN Composites by Spark Plasma Sintering

2008 ◽  
Vol 403 ◽  
pp. 241-242
Author(s):  
Mikinori Hotta ◽  
Takashi Goto
Keyword(s):  
Phase Transformation ◽  
Boron Nitride ◽  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
Hexagonal Boron Nitride ◽  
Cubic Boron Nitride ◽  
Holding Time ◽  
Theoretical Density ◽  
Plasma Sintering ◽  
Spark Plasma

SiAlON-cubic boron nitride (cBN) composite was prepared by spark plasma sintering (SPS) using -SiAlON and cBN powders as starting materials, and the effect of holding time on densification, phase transformation and hardness of the composite was investigated. The SiAlON-cBN composite containing 20 vol% cBN sintered at 1650oC for 60s was densified to >97% of theoretical density. cBN phase transformed to hexagonal boron nitride (hBN) in the SiAlON-cBN composite with increasing holding time at 1650oC. Vickers hardness of the SiAlON-20vol%cBN composite sintered at 1650oC for 60-300s was 17.7GPa, and the hardness decreased with increasing holding time.

scholarly journals Tricalcium Phosphate - Magnesium Interface: Microstructure and Properties

2016 ◽  
Vol 258 ◽  
pp. 412-415 ◽  
Author(s):  
Mariano Casas Luna ◽  
Edgar Benjamin Montúfar Jimenéz ◽  
Miroslava Horynová ◽  
Pavel Gejdoš ◽  
Lenka Klakurková ◽  
...  
Keyword(s):  
Composite Material ◽  
Chemical Composition ◽  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
Tricalcium Phosphate ◽  
Interface Microstructure ◽  
Mechanical Interaction ◽  
Microstructure And Properties ◽  
Plasma Sintering ◽  
Spark Plasma

The fabrication of a composite material based on magnesium (Mg) and tricalcium phosphate is reported in this work. Rods of β-tricalcium phosphate (β-TCP) were processed and consolidated together with pure Mg powder through spark plasma sintering (SPS). The microstructure at the interface, the chemical composition and transformation of the components and the microhardness were analysed. The microstructure of the composite shows two zones with well-defined and continuous interface between them: a ceramic zone composed by β-TCP filled with Mg and the metallic zone constituted by Mg and Mg rich eutectic. Vickers hardness shows the excellent mechanical interaction between the two zones.

Effects of Al3Ti and (Al,Ni)3Ti Addition on the Sintering of TiB2

2012 ◽  
Vol 1373 ◽  
Author(s):  
Masashi Yoshida
Keyword(s):  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
Titanium Diboride ◽  
Direct Link ◽  
Remarkable Improvement ◽  
Plasma Sintering ◽  
Spark Plasma

ABSTRACTTitanium diboride has been sintered using spark plasma sintering (SPS). With the addition of tetragonal Al3Ti or cubic (Al,Ni)3Ti, the Vickers hardness, Hv, of TiB2 increases up to as high as 2000 by the sintering at 1273K, while that of the sample sintered without additives is as low as 20. Such a remarkable improvement is caused by the improvement of direct link between TiB2 grains in addition to the effect that Al3Ti or (Al,Ni)3Ti fills in the space between TiB2 grains and act as a binder.

scholarly journals A Novel Approach by Spark Plasma Sintering to the Improvement of Mechanical Properties of Titanium Carbonitride-Reinforced Alumina Ceramics

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1344
Author(s):  
Magdalena Szutkowska ◽  
Marcin Podsiadło ◽  
Tomasz Sadowski ◽  
Paweł Figiel ◽  
Marek Boniecki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
Titanium Carbonitride ◽  
Plasma Sintering ◽  
Novel Approach ◽  
Zirconia Composites ◽  
Spark Plasma ◽  
Higher Temperature

Ti(C,N)-reinforced alumina-zirconia composites with different ratios of C to N in titanium carbonitride solid solutions, such as Ti(C0.3,N0.7) (C:N = 30:70) and Ti(C0.5,N0.5) (C:N = 50:50), were tested to improve their mechanical properties. Spark plasma sintering (SPS) with temperatures ranging from 1600 °C to 1675 °C and pressureless sintering (PS) with a higher temperature of 1720 °C were used to compare results. The following mechanical and physical properties were determined: Vickers hardness, Young’s modulus, apparent density, wear resistance, and fracture toughness. A composite with the addition of Ti(C0.5,N0.5)n nanopowder exhibited the highest Vickers hardness of over 19.0 GPa, and its fracture toughness was at 5.0 Mpa·m1/2. A composite with the Ti(C0.3,N0.7) phase was found to have lower values of Vickers hardness (by about 10%), friction coefficient, and specific wear rate of disc (Wsd) compared to the composite with the addition of Ti(C0.5,N0.5). The Vickers hardness values slightly decreased (from 5% to 10%) with increasing sintering temperature. The mechanical properties of the samples sintered using PS were lower than those of the samples that were spark plasma sintered. This research on alumina–zirconia composites with different ratios of C to N in titanium carbonitride solid solution Ti(C,N), sintered using an unconventional SPS method, reveals the effect of C/N ratios on improving mechanical properties of tested composites. X-ray analysis of the phase composition and an observation of the microstructure was carried out.

Effects of Milling Time on Microstructure and Mechanical Properties of Composite WC-(Fe3Al-B) Consolidated by Spark Plasma Sintering

2017 ◽  
Vol 899 ◽  
pp. 487-492
Author(s):  
Luis Antonio C. Ybarra ◽  
Afonso Chimanski ◽  
Gilberto J. Pereira ◽  
Izabel Fernanda Machado ◽  
Humberto Naoyuki Yoshimura
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
Milling Time ◽  
Iron Aluminide ◽  
Plasma Sintering ◽  
Hard Metals ◽  
Spark Plasma ◽  
Vibration Milling

Cobalt is widely used to produce WC-Co hard metals, but this binder has problems of shortage and unstable price. In this work, cobalt was replaced by an iron aluminide intermetallic binder. WC-10%(Fe3Al-3%B) composite was prepared by vibration milling of WC, Fe, Fe-B, and Al powders and sintered by spark plasma sintering (SPS) at 1150 °C for 8 min under 30 MPa. The milling time was 0.17, 12, 25 and 50 h. The SPS was efficient to consolidate the composite resulting in relative density of ~98% or higher. With increasing milling time, Vickers hardness (HV30) of composite increased from 12 to 14 GPa due to the enhanced homogeneity of microstructure, while the fracture toughness, KIc, determined by an indention fracture method using Shetty equation, remained constant at around 9.1 MPa.m1/2.

Tribological Properties of Aluminum and Silicon Borides at High Temperatures

2018 ◽  
Vol 941 ◽  
pp. 1984-1989
Author(s):  
Takashi Murakami ◽  
Atsushi Korenaga ◽  
Tsuguyori Ohana ◽  
Haruyuki Inui
Keyword(s):  
Spark Plasma Sintering ◽  
Tribological Properties ◽  
Vickers Hardness ◽  
The Other ◽  
Temperature Range ◽  
Plasma Sintering ◽  
Gas Atmosphere ◽  
Spark Plasma ◽  
Ar Gas ◽  
Worn Surfaces

In our present study, AlB12 and SiB6 plate specimens prepared by spark plasma sintering AlB12 and SiB6 powders, respectively, and their tribological properties were investigated in the temperature range of 25°C to 1000°C in air. Also, the micro Vickers hardness of the AlB12 and SiB6 plate specimens were evaluated in the temperature range of 25°C to 1000°C in an Ar gas atmosphere. It was found that both the steady friction coefficients of the AlB12 and SiB6 plate specimens were as low as 0.07 to 0.08 at 1000°C. According to XPS analyses, it was found that Al2O3 and B2O3 films were observed on the worn surfaces of the AlB12 plate specimens after sliding at 1000°C. On the other hand, SiO2 and B2O3 films were observed on the worn surfaces of the SiB6 plate specimens after sliding at the same temperature. It was also found that both the boride plate specimens exhibited micro Vickers hardness as high as 20 GPa in the temperature range of 25°C to 1000°C.

Spark Plasma Sintering of βSiAlON-cBN Composite

2007 ◽  
Vol 561-565 ◽  
pp. 599-602 ◽  
Author(s):  
Mikinori Hotta ◽  
Takashi Goto
Keyword(s):  
Phase Transformation ◽  
Boron Nitride ◽  
Spark Plasma Sintering ◽  
Firing Temperature ◽  
Vickers Hardness ◽  
Cubic Boron Nitride ◽  
Theoretical Density ◽  
Maximum Value ◽  
Plasma Sintering ◽  
Spark Plasma

βSiAlON-cubic boron nitride (cBN) composites were prepared from β-SiAlON and cBN powders using spark plasma sintering (SPS) at firing temperature of 1600-1900oC under pressure of 100MPa, and densification, phase transformation and hardness of the composites were investigated. The phase transformation of cBN to hexagonal BN (hBN) was inhibited in βSiAlON-cBN composite. βSiAlON-cBN composites containing 10-30 vol% cBN fired at 1650oC were densified to 95-98% of theoretical density with no transformation of cBN to hBN. Vickers hardness of the βSiAlON-cBN composite containing 20 vol% cBN fired at 1650oC was 17.5 GPa in maximum value, and the hardness significantly decreased as cBN phase was transformed to hBN in the composites.

Tailoring Plate-Like Grained ZrB2 Ceramic via a Strong Magnetic Field Alignment Method Followed by Spark Plasma Sintering

2012 ◽  
Vol 512-515 ◽  
pp. 702-705
Author(s):  
Chun Feng Hu ◽  
Qing Huang ◽  
Guo Jun Zhang ◽  
Yoshio Sakka
Keyword(s):  
Magnetic Field ◽  
Strong Magnetic Field ◽  
Spark Plasma Sintering ◽  
Side Surface ◽  
Hardness Measurement ◽  
Orientation Factor ◽  
Alignment Method ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Anisotropic Mechanical Property

Through strong magnetic field alignment (SMFA) method followed by spark plasma sintering (SPS), dense tailored ZrB2 ceramic could be prepared using the plate-like grains as initial material. The measured Lotgering orientation factor f(00l) on the textured top surface (TTS) was high as 0.62 and f(hk0) on the textured side surface (TSS) was 0.65. Vickers hardness measurement showed the anisotropic mechanical property of textured sample. On the TTS, the hardness was 13.4 ± 0.9 GPa, while on the TSS the hardness was 12.0 ± 0.9 GPa.

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