Ultrafine Cemented Carbides with Cobalt and Iron Binders Prepared via Reactive In Situ Sintering

2021 ◽  
Vol 320 ◽  
pp. 176-180
Author(s):  
Marek Tarraste ◽  
Jakob Kübarsepp ◽  
Arvo Mere ◽  
Kristjan Juhani ◽  
Märt Kolnes ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Thermal Activation ◽  
High Energy ◽  
Cemented Carbides ◽  
Reactive Sintering ◽  
Plasma Sintering ◽  
Ultrafine Grained ◽  
Spark Plasma ◽  
Ultrafine Grained Microstructure

Reactive sintering of cemented carbides involves mechanical and thermal activation of precursor elemental powders, followed by in-situ synthesis of tungsten carbide. This approach promotes formation of ultrafine microstructure favored in many cemented carbide applications. Our study focuses on the effect of mechanical activation (high-energy milling) on the properties of powder and following thermal activation (sintering) on the microstructure characteristics and phase composition. Reactive sintering proved effective – an ultrafine grained microstructure of cemented carbides with Co and Fe binders was achieved. Formation of tungsten carbide grains was complete at low temperature during reactive spark plasma sintering, resulting in textured microstructure with anisotropic grain formation and growth.

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.

Reactive Sintering of TaB2 Using Spark Plasma Sintering Method

2014 ◽  
Vol 88 ◽  
pp. 54-59 ◽  
Author(s):  
Jolanta Laszkiewicz-Łukasik ◽  
Lucyna Jaworska ◽  
Piotr Putyra ◽  
Barbara Smuk
Keyword(s):  
Spark Plasma Sintering ◽  
High Energy ◽  
Tantalum Powder ◽  
Composition Analysis ◽  
Reactive Sintering ◽  
Boron Powder ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
High Level ◽  
Sintering Method

Tantalum diboride was synthesized and sintered from metallic tantalum powder and amorphous boron powder in one technological process using Spark Plasma Sintering method. The precursors were: tantalum with grain size below 5μm and boron with particle size in the range of 1-2μm. Tantalum powder, before mixing with boron, was subjected to high-energy milling under argon atmosphere in order to reduce specific surface area. The process should be carried out without air, due to protection against the influence of oxygen. During reactive sintering SPS process oxidation participation should be limited because of high exothermic reactions. Morphologies of the powders before and after milling were studied using SEM. Reactive sintering processes were carried out at temperatures from 1800°C up to 2200°C at 48MPa. Sintering duration was in the range of 1-30min. Volume changes of samples and temperature increase during the synthesis were observed and determined. The result of X-Ray phase composition analysis and microstructure observations using SEM are presented. Relative density, Young's modulus, Vickers hardness and fracture toughness of the materials were determined. During the reactive sintering the material of only one phase TaB2, with high level of densification, was obtained.

In Situ Synthesis of Alumina Matrix Composites by Spark Plasma Sintering

2013 ◽  
Vol 750 ◽  
pp. 92-95
Author(s):  
Zhong Chun Chen ◽  
Sri Nugroho ◽  
Akira Kawasaki
Keyword(s):  
Spark Plasma Sintering ◽  
Matrix Composites ◽  
Reactive Sintering ◽  
Alumina Matrix ◽  
Grain Sizes ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Al2o3 Phase ◽  
Al2o3 Matrix

Al2O3 matrix composites reinforced with Ba-b-Al2O3 phase were synthesized through reactive sintering using Al2O3 and BaCO3 as starting powders. Dense Al2O3/Ba-b-Al2O3 composites can be obtained by spark plasma sintering from Al2O3/BaO•Al2O3 powder, which was prepared by calcining Al2O3/BaCO3 powder mixture. The Ba-b-Al2O3 reinforcing phase exhibited an elongated morphology due to preferred diffusion of Ba cations. The existence of Ba-b-Al2O3 phase as well as low sintering temperature and short holding time during reactive sintering inhibit grain growth and thus result in small grain sizes of the Al2O3 matrix.

The Cu Matrix Strengthened by TiH2–C In-Situ Synthesized via Mechanical Milling and Spark Plasma Sintering

2021 ◽  
Vol 21 (4) ◽  
pp. 2687-2691
Author(s):  
Nguyen Thi ◽  
Hoang Oanh ◽  
Nguyen Hoang Viet
Keyword(s):  
Spark Plasma Sintering ◽  
Mechanical Milling ◽  
Sintering Temperature ◽  
Annealing Treatment ◽  
High Energy ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Tic Nanoparticles

The present work is focused on the fabrication and the investigation of microstructures of copperbased TiC nanocomposites produced by mechanical milling in a high energy planetary ball mill. TiH2, carbon and copper powders were used as starting materials in which In-Situ reaction between carbon and TiH2 occurs to form TiC nanoparticles. The mixture powders of Cu–TiH2–C were milled for 12 h at 450 rpm in Argon gas. Annealing treatment process at 950 °C for 2 h was applied for as-milled composite powders to enhance In-Situ reaction. The consolidation of composite powders was conducted by spark plasma sintering under uniaxial pressing of 70 MPa. Sintering procedure was done at 950 and 1000 °C for 5 min. The results indicated that as TiC nanoparticles are formed after sintering at 950 °C and the TiC particles are increased up at higher sintering temperature of 1000 °C. Fracture surface of sintered samples shows ductile mode. HR-TEM image showed the crystal size of copper was about 10 nm for sample sintered at 1000 °C. The hardness and relative density of the nanocomposites increase when increasing sintering temperature.

Mechanical Behavior of TiB2 Nanoparticles Reinforced Cu Matrix Composites Synthesized by In-Situ Processing

2006 ◽  
Vol 510-511 ◽  
pp. 346-349 ◽  
Author(s):  
Dae Hwan Kwon ◽  
Khoa Xuan Huynh ◽  
Thuy Dang Nguyen ◽  
Pyuck Pa Choi ◽  
Myung-Gyu Chang ◽  
...  
Keyword(s):  
Copper Matrix ◽  
High Energy ◽  
Matrix Composites ◽  
Mechanical And Electrical Properties ◽  
Plasma Sintering ◽  
High Temperature Synthesis ◽  
Spark Plasma ◽  
Nanocomposite Powders ◽  
Tib2 Particles

Cu-TiB2 nanocomposite powders were in situ synthesized by combining high-energy ball milling of Cu-Ti-B elemental powder mixtures as precursors and subsequent self-propagating high temperature synthesis (SHS). Cu-40wt.% TiB2 was produced after SHS reaction and then diluted by copper to obtain desired homogeneous composites with 2.5, 5 and 10wt.%TiB2. Spark plasma sintering (SPS) was used to inhibit grain growth and thereby obtain fully Cu-TiB2 sintered bodies with nanocomposite structure. After SHS reaction, only Cu and TiB2 phases were detected in the SHS-product. Spheroidal TiB2 particles smaller than 250nm were formed in the copper matrix after SHS-reaction. Mechanical and electrical properties were investigated after SPS at 650°C for 30min under 50MPa. The electrical conductivity decreased from 75 to 54% IACS with increasing of TiB2 contents from 2.5 to 10wt.%. However, hardness increased from 56 to 97HRB. In addition, the tensile strength increased with increasing the TiB2 content.

Ultrafine-grained Ti66Nb13Cu8Ni6.8Al6.2 composites fabricated by spark plasma sintering and crystallization of amorphous phase

2009 ◽  
Vol 24 (6) ◽  
pp. 2118-2122 ◽  
Author(s):  
Y.Y. Li ◽  
C. Yang ◽  
W.P. Chen ◽  
X.Q. Li ◽  
S.G. Qu
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Spark Plasma Sintering ◽  
Amorphous Phase ◽  
Fracture Strength ◽  
High Fracture ◽  
Plasma Sintering ◽  
Ultrafine Grained ◽  
Spark Plasma

We report on the formation of ultrafine-grained Ti66Nb13Cu8Ni6.8Al6.2 composites with in situ precipitated micrometer-sized β-Ti(Nb) phase by spark plasma sintering with crystallization. Microstructure analysis indicated that all alloys consisted of soft (Cu, Ni)Ti2 regions surrounded by hard β-Ti(Nb) regions but displayed different microstructures. The alloys exhibited high fracture strength of more than 2200 MPa and remarkable plasticity of ∼25%. The results provided a promising method for fabricating large-sized bulk composites with excellent mechanical properties by powder metallurgy.

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