scholarly journals Zirconium alloyed tungsten borides synthesized by spark plasma sintering

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dariusz Garbiec ◽  
Maria Wiśniewska ◽  
Rafał Psiuk ◽  
Piotr Denis ◽  
Neonila Levintant-Zayonts ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Spark Plasma Sintering ◽  
Wear Test ◽  
Holding Time ◽  
Phase Identification ◽  
High Heating Rate ◽  
Plasma Sintering ◽  
The Coefficient Of Friction ◽  
Spark Plasma ◽  
Tungsten Borides

AbstractTungsten borides (WBx; x = 2.5 or 4.5) with an increasing substitution of tungsten by zirconium from 0 to 24 at.% were synthesized by spark plasma sintering (SPS) for the first time. The influence of the holding time (2.5–30 min) on the densification behavior, microstructure evolution and development of the properties of W–Zr–B compounds were studied. The samples were characterized using scanning electron microscopy (SEM) for microstructure analysis, X-ray diffraction (XRD) for phase identification, Vickers micro-indentation for microhardness measurements, tribological tests to determine the coefficient of friction and specific wear rate, as well as measurements of electrical conductivity. The XRD results confirm the presence of the WB4 phase in the microstructure, despite the high sintering temperature (1800 °C) and small overstoichiometric excess of boron (4.5) addition in the sintered samples. This is caused by the high heating rate (400 °C/min), short holding time (2.5 min) and addition of zirconium. The Vickers hardness (HV) values measured at 1 N are 24.8 ± 2.0 and 26.6 ± 1.8 GPa for 24 at.% zirconium in WB2.5 and for 0 at.% zirconium in WB4.5, respectively. In addition, the hardest sample (W0.76Zr0.24B2.5) showed electrical conductivity up to 3.961·106 S/m, which is similar to WC–Co cemented carbides. The friction and wear test results reveal the formation of a boron-based film which seems to play the role of a solid lubricant.

scholarly journals Enhancement of Electrical Conductivity of Aluminum-Based Nanocomposite Produced by Spark Plasma Sintering

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1150
Author(s):  
Nicolás A. Ulloa-Castillo ◽  
Roberto Hernández-Maya ◽  
Jorge Islas-Urbano ◽  
Oscar Martínez-Romero ◽  
Emmanuel Segura-Cárdenas ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Spark Plasma Sintering ◽  
Experimental Tests ◽  
Powder Morphology ◽  
Plasma Sintering ◽  
Multi Walled Carbon Nanotubes ◽  
Spark Plasma ◽  
Ball Milling Technique ◽  
Walled Carbon Nanotubes

This article focuses on exploring how the electrical conductivity and densification properties of metallic samples made from aluminum (Al) powders reinforced with 0.5 wt % concentration of multi-walled carbon nanotubes (MWCNTs) and consolidated through spark plasma sintering (SPS) process are affected by the carbon nanotubes dispersion and the Al particles morphology. Experimental characterization tests performed by scanning electron microscopy (SEM) and by energy dispersive spectroscopy (EDS) show that the MWCNTs were uniformly ball-milled and dispersed in the Al surface particles, and undesirable phases were not observed in X-ray diffraction measurements. Furthermore, high densification parts and an improvement of about 40% in the electrical conductivity values were confirmed via experimental tests performed on the produced sintered samples. These results elucidate that modifying the powder morphology using the ball-milling technique to bond carbon nanotubes into the Al surface particles aids the ability to obtain highly dense parts with increasing electrical conductivity properties.

Production of Dispersion-Strengthened Cu-TiB2 Alloys by Ball-Milling and Spark-Plasma Sintering

2007 ◽  
Vol 534-536 ◽  
pp. 1489-1492 ◽  
Author(s):  
Dae Hwan Kwon ◽  
Jong Won Kum ◽  
Thuy Dang Nguyen ◽  
Dina V. Dudina ◽  
Pyuck Pa Choi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ball Milling ◽  
Spark Plasma Sintering ◽  
Ball Mill ◽  
Milling Time ◽  
Rotation Speed ◽  
Sintering Temperature ◽  
Milled Powder ◽  
Plasma Sintering ◽  
Spark Plasma

Dispersion-strengthened copper with TiB2 was produced by ball-milling and spark plasma sintering (SPS).Ball-milling was performed at a rotation speed of 300rpm for 30 and 60min in Ar atmosphere by using a planetary ball mill (AGO-2). Spark-plasma sintering was carried out at 650°C for 5min under vacuum after mechanical alloying. The hardness of the specimens sintered using powder ball milled for 60min at 300rpm increased from 16.0 to 61.8 HRB than that of specimen using powder mixed with a turbular mixer, while the electrical conductivity varied from 93.40% to 83.34%IACS. In the case of milled powder, hardness increased as milling time increased, while the electrical conductivity decreased. On the other hand, hardness decreased with increasing sintering temperature, but the electrical conductiviey increased slightly

Evaluation of Wear and Corrosion Behaviour of Hybrid Sintered Ti6Al4V Alloy

2019 ◽  
Vol 821 ◽  
pp. 321-326
Author(s):  
Olusoji Oluremi Ayodele ◽  
Mary Ajimegoh Awotunde ◽  
Mxolisi Brendon Shongwe ◽  
Adewale Oladapo Adegbenjo ◽  
Bukola J. Babalola ◽  
...  
Keyword(s):  
Corrosion Behaviour ◽  
Wear Test ◽  
Sintered Compact ◽  
Plasma Sintering ◽  
Wear And Corrosion ◽  
The Coefficient Of Friction ◽  
Spark Plasma ◽  
Worn Surface ◽  
Material Wear ◽  
Sintered Materials

Ti6Al4V alloy was consolidated by hybrid spark plasma sintering at a temperature of 1200 °C, pressure of 50 MPa, holding time of 5 min and heating rate of 100 °C/min. This resulted in the maximum value of sintered density. Microstructural evolutions of the sintered compact were analysed with SEM. Sliding wear test were accomplished at different sliding loads of 5, 8 and 10 N using ball on disc tribometer configuration with stainless steel as the counterface material. Wear debris obtained was found to contain mostly the sintered materials with minute traces of the counterface material. The coefficient of friction reaches the maximum with increase in applied load. Worn surface analyses revealed the wear mechanism was abrasive. The potentiodynamic polarisation of the sintered compact showed the sintered compact in 0.9 wt % NaCl solution exhibited more resistance to corrosion.

scholarly journals Microstructure Evolution and Mechanical Properties of Spark Plasma Sintered Manganese Addition on Ti-48Al-2Cr-2Nb Alloys

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1577
Author(s):  
A. Raja Annamalai ◽  
Muthe Srikanth ◽  
Raunak Varshney ◽  
Mehta Yash Ashokkumar ◽  
Swarup Kumar Patro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Titanium Aluminide ◽  
Sem Analysis ◽  
Tensile Fracture ◽  
Nominal Composition ◽  
High Heating Rate ◽  
Main Task ◽  
Plasma Sintering ◽  
Spark Plasma

Titanium aluminide (TiAl) is one of the most promising materials for aerospace applications. It is a suitable replacement for nickel-based superalloys predominantly used in these applications. Titanium aluminide with superior processability is the main task in carrying out this work. A less brittle TiAl alloy was fabricated using spark plasma sintering by adding the nominal composition (2.5, 5, and 7.5 wt.%) of manganese (Mn) to Ti-48Al-2Cr-2Nb. The samples were sintered at 1150 °C using spark plasma sintering (SPS), which helped produce highly dense models with fine grain sizes at the high heating rate (here, 100 °C per minute). The effects produced by Mn additions on the densification, mechanical properties (yield strength, hardness, and % elongation), and microstructure of the Ti aluminide alloys are studied. Scanning electron microscopy (SEM) has been used to explore the sintered samples’ microstructures. The alloyed materials are entirely dissolved in the gamma matrix due to the manganese approaching its melting point. XRD and SEM analysis confirmed the new intermetallic related to Mn neither with titanium nor aluminum. The enhancement of % elongation at break is evident for the little improvement in the ductility of TiAl by the addition of Mn. The samples’ tensile fracture nature is also evidence for enhancement in the alloy’s % elongation.

scholarly journals Tribological Properties of Ti2AlNb Matrix Composites Containing Few-Layer Graphene Fabricated by Spark Plasma Sintering

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 924
Author(s):  
Wei Wang ◽  
Ziru Han ◽  
Qingjuan Wang ◽  
Baojia Wei ◽  
Shewei Xin ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Tribological Properties ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Layer Graphene ◽  
Plasma Sintering ◽  
Ti2alnb Alloy ◽  
The Coefficient Of Friction ◽  
Spark Plasma ◽  
Few Layer Graphene

Ti2AlNb alloys with few-layer graphene were fabricated by spark plasma sintering (SPS) to enhance the tribological properties (TP) of the composite materials. Microstructure characteristics of the original few-layer graphene (FLG), Ti2AlNb powders, and the sintered composites were characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy. The experimental results indicated that FLGs were homogeneously distributed in the composites. Tribological results indicated that the coefficient of friction (COF) of the composites was reduced as the content of FLG increased. Compared with the pure Ti2AlNb alloy, the average COF of the composite with 1.0 wt.% FLG was decreased by 9.4% and the wear rate was decreased by 36%. Meanwhile, the microstructures of the worn surface showed that TiC particles and friction layers formed by residual FLGs were present on the surface of the composites after tribological test. It is proposed that Ti2AlNb alloys with FLGs presented the enhanced wear resistance.

Effects of Processing Parameters of SPS on the Densification and Texture of LaPO4 Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 1059-1061 ◽  
Author(s):  
Ai Bing Du ◽  
Zhi Xue Qu ◽  
Chun Lei Wan ◽  
Ruo Bing Han ◽  
Wei Pan
Keyword(s):  
Relative Density ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Processing Parameters ◽  
Preferred Orientation ◽  
Holding Time ◽  
Plasma Sintering ◽  
Spark Plasma

Spark plasma sintering was used to fabricate the LaPO4 ceramics and the effect of SPS holding time and sintering temperature on the densification and texture of LaPO4 ceramics were studied. The results revealed that holding time had no obvious influence on the densification of LaPO4 ceramics under the present process. The density increases with the increase of sintering temperature, when it reached 1350°C, the relative density kept nearly constant of 98.6 %. The preferred orientation of LaPO4 ceramics approximately increases with the increase of sintering temperature, but contrary impact in holding time.

Thermoelectric Properties of Ag1-xPbmSbTe2+m Compounds

2007 ◽  
Vol 336-338 ◽  
pp. 854-856
Author(s):  
Yong Gao Yan ◽  
Xin Feng Tang ◽  
Hai Jun Liu ◽  
Ling Ling Yin ◽  
Qing Jie Zhang
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
M 10 ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Type Conduction

Ag1-xPbmSbTe2+m (m = 6, 10, 18; x = 0, 0.5, 0.75) compounds were prepared by melting-spark plasma sintering (SPS) process. The effects of m and x on the thermoelectric properties of the compounds were investigated. The results indicate that all samples are n-type conduction. For Ag1-xPb18SbTe20 (x = 0, 0.5, 0.75), the electrical conductivity decreases, whereas Seebeck coefficient increases, with increasing Ag concentration. For AgPbmSbTe2+m (m = 6, 10, 18), as m increases, the Seebeck coefficient slightly decreases and the electrical conductivity increases first, with a maximum at m =10, and then decreases. The thermal conductivity increases with increasing m.

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