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.

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.

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.

Sintering Performance and Mechanical Properties of Titanium Compacts Prepared by Spark Plasma Sintering

2012 ◽  
Vol 706-709 ◽  
pp. 217-221 ◽  
Author(s):  
Hiroshi Izui ◽  
Genki Kikuchi
Keyword(s):  
Mechanical Properties ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Tensile Property ◽  
Density Ratio ◽  
Alloying Elements ◽  
Blended Elemental ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Stabilizing Element

Titanium alloys were produced by blended elemental powder metallurgy (P/M) method. We focused on the effect of alloying elements (Fe, Mo, and Al) on the consolidation and mechanical properties of Ti compacts prepared by spark plasma sintering. The effects of amount of alloying elements and sintering temperature on the relative density and tensile properties of Ti compacts were investigated. The addition of β-stabilizing elements (Fe and Mo) significantly improved the densification of Ti compacts, where the relative density ratio of Ti-5 wt% Mo specimen became higher than 99.9 %, and Ti-5 wt% Fe specimen higher than 99.0 %. On the other hand, the addition of Al as α-stabilizing element led to improve the relative density of Ti-5 wt% Al compact with higher than 99.9 %. The tensile property for sintered Ti-5 wt% Mo compact had the highest elongation of 16 %. It will be discussed the microstructures and tensile property of the compacts.

Effect of VC Addition on Microstructure and Mechanical Properties of Ultrafine Grained WC-Co Alloys

2014 ◽  
Vol 893 ◽  
pp. 444-448 ◽  
Author(s):  
Xue Mei Liu ◽  
Xiao Yan Song ◽  
Hai Bin Wang ◽  
Yang Gao ◽  
Yao Wang
Keyword(s):  
Mechanical Properties ◽  
Composite Powder ◽  
Cemented Carbides ◽  
Comprehensive Properties ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Ultrafine Grained ◽  
Spark Plasma ◽  
Co Alloys

This study was focused on the effect of VC addition on the microstructure and mechanical properties of the prepared ultrafine grained cemented carbides. VC was added to the rawoxide materials which were synthesized to the WC-Co composite powder by the in-situ reduction and carbonization process. The ultrafine grained WC-Co alloys were fabricated by the spark plasma sintering technique using the prepared WC-Co composite powder. The phase constitution, microstructure characteristics and mechanical properties of the sintered ultrafine grained cemented carbides were analyzed quantitatively. The study proposed that VC plays a significant role in decreaseing the grain size of the prepared WC-Co alloy. The ultrafine grained WC-Co alloy with high comprehensive properties can be obtained as an appropriate addition of VC in the developed process.

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