Effect of Alumina Additions on Mechanical and Electrical Properties of 8mol% Yttria-Stabilized Zirconia Prepared by Spark Plasma Sintering

2006 ◽  
Vol 317-318 ◽  
pp. 917-920
Author(s):  
Jae Kwang Kim ◽  
Kyung Hun Kim ◽  
Yong Ho Choa ◽  
Jong Won Yoon ◽  
Kwang Bo Shim
Keyword(s):  
Electrical Conductivity ◽  
Grain Size ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Average Particle Size ◽  
Yttria Stabilized Zirconia ◽  
Average Particle ◽  
Stabilized Zirconia ◽  
Plasma Sintering ◽  
Spark Plasma

Dense 8mol% yttria-stabilized zirconia (8YSZ) consisting of submicrometer-sized grains was prepared using spark plasma sintering (SPS) along with Al2O3 additives. The starting powder with average particle size of 50nm was densified to 98% of the relative density with short sintering time (5min) at 1200 while preserving a submicrometer grain size. The fracture toughness and bending strength showed maximum values of 2.54MPam1/2 and 380MPa at 2vol% alumina-added 8YSZ, due mainly to the higher relative density and small grain size. The electrical conductivity of 2vol% alumina-added 8YSZ was 0.0278 S/cm at 700 in airThus, alumina additions in 8YSZ using the SPS method are an effective process to improve the mechanical strength and electrical conductivity.

Spark-Plasma Sintering of Molybdenum Disilicide

2005 ◽  
Vol 287 ◽  
pp. 160-165 ◽  
Author(s):  
Ji Soon Kim ◽  
Young Do Kim ◽  
Choong Hyo Lee ◽  
Pyuck Pa Choi ◽  
Young Soon Kwon
Keyword(s):  
Relative Density ◽  
Spark Plasma Sintering ◽  
Silicon Oxide ◽  
Average Particle Size ◽  
Molybdenum Disilicide ◽  
Milling Process ◽  
Average Particle ◽  
Densification Rate ◽  
Plasma Sintering ◽  
Spark Plasma

The effect of milling on the densification behavior of MoSi2 powder during spark-plasma sintering (SPS) was investigated. MoSi2 starting powder with an average particle size of 10 µm was milled to reduce particle sizes to less than 1 µm. Sintering was performed in a SPS facility, varying the sintering temperature from 1200°C to 1500°C. Changes in relative density and the densification rate were measured as a function of temperature. Additionally, the microstructure of sintered compacts was analyzed by means of SEM and EPMA. The sintered density was lower for ballmilled powder compacts (having 94-95% relative density) than for as-received ones (having 94- 98% relative density) despite a higher densification rate of the former in the early and middle stages of sintering. These apparently contradictory results can be explained by a pick-up of oxygen (from 0.3 to 1.8 wt. % O) during the milling process, leading to the formation of silicon oxide and its decomposition into a gas phase at temperatures above 1200°C.

scholarly journals Two-Step Spark Plasma Sintering Process of Ultrafine Grained WC-12Co-0.2VC Cemented Carbide

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2443 ◽  
Author(s):  
Zhenhua Wang ◽  
Jiheng Jia ◽  
Boxiang Wang ◽  
Yulin Wang
Keyword(s):  
Mechanical Properties ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Average Particle Size ◽  
Cemented Carbide ◽  
Cemented Carbides ◽  
Average Particle ◽  
Plasma Sintering ◽  
Ultrafine Grained ◽  
Spark Plasma

Ultrafine grained WC-12Co-0.2VC (named UYG12V) cemented carbides were prepared via the two-step spark plasma sintering (SPS) in this study. First, the effects of the sintering temperature on the relative density and WC grain size of UYG12V cemented carbides were studied. The results show that regular WC grains form when sintered at 1300 °C. The sintered body begins to rapidly densify and WC grains grow slowly when sintered at 1200 °C. Thus, the first-step (T1) and the second-step (T2) temperatures in the two-step SPS of UYG12V are 1300 °C and 1200 °C, respectively. The effect of the holding time during the first and second steps on the mechanical properties was also studied. The results show that the UYG12V cemented carbide sintered at 1300 °C for 3 min and then at 1200 °C for 5 min has the best comprehensive mechanical properties, exhibiting the average particle size, Vickers hardness, fracture toughness, relative density, and bending strength of 271 nm, 18.06 GPa, 12.25 MPa m1/2, 99.49%, and 1960 MPa, respectively.

Processing of Swnt-Reinforced Yttria Stabilized Zirconia by Spark Plasma Sintering and Microstructure Characterization

2012 ◽  
Vol 18-19 ◽  
pp. 317-323 ◽  
Author(s):  
S. de Bernardi-Martín ◽  
R. Poyato ◽  
Diego Gómez-García ◽  
Arturo Domínguez-Rodríguez
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Ceramic Materials ◽  
Ceramic Composites ◽  
Yttria Stabilized Zirconia ◽  
Zirconia Ceramic ◽  
Stabilized Zirconia ◽  
Single Wall Carbon ◽  
Plasma Sintering ◽  
Spark Plasma

Single wall carbon nanotube reinforced yttria stabilized zirconia ceramic materials have been obtained by means of spark plasma sintering technique. Single wall carbon nanotubes were treated in an acid solution before mixing with zirconia powders to obtain a uniform distribution of both powders. This method allows obtaining ceramic materials with a grain size between 200 nanometers and 1 micron and with a grain size distribution which depends on processing conditions. This new route opens a new perspective for new ceramic composites tailoring with enhanced mechanical properties as structural materials

Synthesis and Densification of Nano-Sized W Powders Prepared by Hydrogen Reduction of Ball-Milled WO3 Powders

2020 ◽  
Vol 20 (7) ◽  
pp. 4521-4524
Author(s):  
Ju-Yeon Han ◽  
Hyunji Kang ◽  
Young-Keun Jeong ◽  
Sung-Tag Oh
Keyword(s):  
Relative Density ◽  
Spark Plasma Sintering ◽  
Hydrogen Reduction ◽  
Average Particle Size ◽  
Applied Pressure ◽  
Average Particle ◽  
Tem Analysis ◽  
Combination Process ◽  
Plasma Sintering ◽  
Spark Plasma

The synthesis and consolidation of nano-sized W powders are attempted with the combination process of hydrogen reduction of ball-milled WO3 powder and spark plasma sintering. The reduction behavior of WO3 is analyzed by temperature-programmed reduction. The reaction peaks for reduction of WO3 are observed in the temperature range of 590–782 °C. XRD and TEM analysis reveals that oxide powder is changed to metallic W with an average particle size of 100 nm by hydrogen reduction at 900 °C for 1 h. The densified specimen by spark plasma sintering at 1700 °C under an applied pressure of 50 MPa using nano-sized W powder shows increased relative density compared with that using micron-sized W powder. The results suggested that the W bulk with increased relative density fine microstructure can be fabricated by spark plasma sintering of hydrogen-reduced WO3 powder, more effectively.

Mechanical Property of Porous Titanium Produced by Spark Plasma Sintering

2008 ◽  
Vol 385-387 ◽  
pp. 637-640 ◽  
Author(s):  
Yuki Sakamoto ◽  
Shigeaki Moriyama ◽  
Masahiro Endo ◽  
Yuji Kawakami
Keyword(s):  
Elastic Modulus ◽  
Spark Plasma Sintering ◽  
Average Particle Size ◽  
Pure Titanium ◽  
Porous Titanium ◽  
Human Bone ◽  
Average Particle ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Biological Reaction

Titanium has widely been used as a biomaterial because of its excellent corrosion resistance and biocompatibility. However, problems with respect to biological reaction and fitness of elastic modulus for human bone or tooth have yet to be solved. Porous titanium is expected to be a promising material to solve these problems. The aim of this study is to clarify the effect of the porous structure of this material on the biomechanical compatibility. The spherical pure titanium powder, with an average particle size of 100 µm, was sintered by spark plasma sintering. The sintered porous titanium compacts had a porosity of 33 %. The specimens were machined from the sintered compacts for the evaluation of the mechanical properties. The elastic modulus indicated a value close to human bone, while the tensile and compressive strengths showed lower values than those of human bone.

Spark Plasma Sintering of Yttria-Stabilized Zirconia/Titanium Nitride Composites

2015 ◽  
Vol 1735 ◽  
Author(s):  
Paulo S. M. Silva ◽  
Fabio C. Fonseca
Keyword(s):  
Titanium Nitride ◽  
Spark Plasma Sintering ◽  
Yttria Stabilized Zirconia ◽  
X Rays ◽  
Stabilized Zirconia ◽  
Electrical Measurements ◽  
Mechanical Mixing ◽  
Metallic Behavior ◽  
Plasma Sintering ◽  
Spark Plasma

ABSTRACTComposites of 8 mol% yttria-stabilized zirconia (YSZ) and titanium nitride (TiN) were obtained by mechanical mixing of commercial powders. High-density samples of (1-x) YSZ / x TiN, with x = 0, 25, 50, and 75 wt.%, were obtained by spark plasma sintering (SPS) at 1450 °C for 5 min. Surface contamination with carbon from the SPS was eliminated by diamond sawing of parallel surfaces. X-rays diffraction analyses showed that samples are composed by a mixture of the initial phases, without appreciable reaction as inferred from calculated lattice parameters. dc 4-probe electrical measurements in the 100-850°C under showed that samples have a metallic behavior, indicating that the percolation threshold was attained for the sample with the lowest content of the TiN (x=25 wt.%), which corresponds to ∼27 vol.%.

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