Effect of Copper Content on the Microstructures and Properties of TiB2 Based Cermets by SHS

2005 ◽  
Vol 475-479 ◽  
pp. 1619-1622 ◽  
Author(s):  
Qiang Xu ◽  
Xing Hong Zhang ◽  
Jie Cai Han ◽  
Wei Pan
Keyword(s):  
Copper Content ◽  
Hot Isostatic Pressing ◽  
Metallic Phase ◽  
Bend Strength ◽  
Temperature Synthesis ◽  
Boron Powder ◽  
High Temperature Synthesis ◽  
Effect Of Copper ◽  
Tib2 Particles ◽  
Toughness Improvement

TiB2 based cermets with different copper content were produced from titanium powder, boron powder and copper powder by Self-propagating High-temperature Synthesis under conditions of Pseudo Hot Isostatic Pressing (SHS/PHIP). In order to obtain the optimal copper content, the effect of copper content on the microstructures and properties of TiB2 based cermets was investigated. The size of the TiB2 particles in the products decreased with increasing amounts of copper. The hardness (HRA) and bend strength increased firstly, then decreased with copper increasing. Their maximum values appeared at 20 wt.% and 40 wt.% copper, respectively. The porosity of TiB2 based cermets decreased with the copper content increasing due to good fluidity of copper. With the addition of copper, the fracture toughness of TiB2 based cermets increased gradually. Crack-tip plastic blunting by a ductile metallic phase and crack deflection are the principal mechanisms of toughness improvement of TiB2 based cermets. The range of optimal copper content in the TiB2 based cermets is between 40 wt.% and 50 wt.%.

Self-Propagating High-Temperature Synthesis of Carbide- and Boride-Aluminides

2006 ◽  
Vol 45 ◽  
pp. 1024-1028 ◽  
Author(s):  
Kiyotaka Matsuura ◽  
Yusuke Hikichi ◽  
Yuki Obara
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Hot Isostatic Pressing ◽  
Average Particle Size ◽  
Average Particle ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
High Temperature Synthesis ◽  
Tic Particle ◽  
Tib2 Particles

TiC- and TiB2-FeAl composites have been produced using the Self-propagating High-temperature Synthesis (SHS) method under Pseudo Hot Isostatic Pressing (PHIP). When mixtures of the elemental powders were heated to a temperature near the melting point of Al under a PHIP of 150 MPa, the powder mixtures exothermically reacted and produced TiC particle dispersed and TiBB2 particle dispersed FeAl-matrix composites. As the volume factions of TiC and TiB2 particles increased from 0.3 to 0.8, the average particle size increased from approximately 1 to 10 μm and the average Vickers hardness increased from approximately 600 to 1600 in both the TiC-FeAl and TiB2-FeAl systems. The application of the PHIP remarkably reduced the porosity of the SHS products. Preheating of the elemental powder mixtures at 773 K for 30 minutes also reduced the porosity. Moreover, the preheating reduced the particle size in the SHS products. It was suggested that degassing of the powder surfaces and mutual diffusion between the different powders should have occurred during the preheating, which led to reduction in pore formation and reduction in heat generation at the SHS reactions, respectively.

Effect of Additives on the Characteristics of Amorphous Nano Boron Powder Fabricated by Self-Propagating High Temperature Synthesis

2015 ◽  
Vol 25 (12) ◽  
pp. 659-665
Author(s):  
Sin Hyong Joo ◽  
Hayk H. Nersisyan ◽  
Tae Hyuk Lee ◽  
Young Hee Cho ◽  
Hong Moule Kim ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Synthesis ◽  
Boron Powder ◽  
Effect Of Additives ◽  
High Temperature Synthesis

scholarly journals Synthesis and characterisation of ultra-hard and lightweight AlMgB14–xTiB2 composites for wear-resistance and ballistic protection

10.30544/132 ◽  
2015 ◽  
Vol 21 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Varužan Kevorkijan ◽  
Srečo Davorin Škapin ◽  
Danilo Suvorov
Keyword(s):  
Normal Pressure ◽  
Reaction Yield ◽  
Maximum Hardness ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Ballistic Protection ◽  
Composites Processing ◽  
Heating Up ◽  
Tib2 Particles ◽  
Future Project

As an alternative to mechanical alloying, high temperature synthesis (HTS) of ultra-hard, super-abrasive AlMgB14 was performed under normal pressure. The reaction mixture consisted of elemental Al and B, whereas Mg was added in the form of a Mgprecursor which liberates elemental magnesium approximately 400 ºC above the melting point of Mg, in this way reducing its evaporation during heating-up. 95 wt % conversion to AlMgB14 and 5 wt % to MgAl2O4 was achieved. The synthesized AlMgB14 baseline powder, as well as mixtures of AlMgB14 consisting of 30, 50 and 70 wt% of TiB2, were hot pressed to near theoretical density. The various samples produced were characterized for microstructure and hardness. A microhardness of 29.4GPa in hot pressed AlMgB14 and a maximum Vickers hardness of 30.2 GPa in hot pressed samples of AlMgB14 reinforced with 70 wt% of TiB2 particles (d50=4,1µm) was achieved. Future project milestones necessary for achieving a higher AlMgB14 reaction yield, reducing the MgAl2O4 content and producing sinter-active AlMgB14 powder, as well as hot pressed composites processing improvement for gaining maximum hardness are also presented.

Isothermal Oxidation Behavior of AlN-TiB2 Ceramics Synthesized by SHS-HIP

2013 ◽  
Vol 575-576 ◽  
pp. 170-173
Author(s):  
Li Juan Zhou ◽  
Yun Xia Zhao ◽  
Hong Bo Li ◽  
Yong Ting Zheng ◽  
Fan Tao Meng
Keyword(s):  
High Temperature ◽  
Oxidation Behavior ◽  
Hot Isostatic Pressing ◽  
Isothermal Oxidation ◽  
Oxidation Products ◽  
Aluminum Borate ◽  
Temperature Synthesis ◽  
Good Oxidation Resistance ◽  
High Temperature Synthesis ◽  
Conductive Ceramics

sothermal oxidation behavior of the AlN-TiB2 conductive ceramics prepared by self-propagating high-temperature synthesis and hot isostatic pressing (SHS-HIP) was evaluated in a temperature range from 900 to 1400 °C for exposure times from 1 to 16 h in air. The oxidation experimental results show that the conductive ceramics have a good oxidation resistance below 1200 °C. The oxidation products on the sample surfaces are mainly composed of Al2TiO5, TiO2 and aluminum borate phases.

Cold and Detonation Spraying of TiB2-Cu Nanocomposites

2007 ◽  
Vol 534-536 ◽  
pp. 1373-1376 ◽  
Author(s):  
O.I. Lomovsky ◽  
Dina V. Dudina ◽  
V. Yu Ulianitsky ◽  
S.B. Zlobin ◽  
V.F. Kosarev ◽  
...  
Keyword(s):  
Particle Size ◽  
Mechanical Milling ◽  
Copper Substrate ◽  
Detonation Spraying ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Future Potential ◽  
Nanocomposite Powders ◽  
Tib2 Particles ◽  
Sprayed Coatings

TiB2-43vol.%Cu nanocomposite powders with titanium diboride particle size 50-100 nm were cold and detonation sprayed in order to fabricate coatings on a copper substrate. The powders were produced by self-propagating high-temperature synthesis (SHS) followed by mechanical milling. The temperatures during spraying were calculated and the change in the nanostructure of the powders during spraying was studied: in cold sprayed coatings the size of TiB2 particles was well retained, in detonation sprayed coatings the growth of the particles was observed, the mode of spraying greatly affecting the microstructure and the size of the particles. The hardness of cold sprayed coatings was higher compared to detonation sprayed coatings. This research shows the future potential for development of coatings with submicron and nanostructure by cold and detonation spraying of powders produced by mechanical milling.

Fabrication of BN-AlN-TiB2 Compound Conductive Ceramics by Self-Propagating High Temperature Synthesis and Hot Isostatic Pressing

2007 ◽  
Vol 336-338 ◽  
pp. 786-789 ◽  
Author(s):  
Li Juan Zhou ◽  
Yong Ting Zheng ◽  
Shan Yi Du
Keyword(s):  
High Temperature ◽  
Composition Dependence ◽  
Bending Strength ◽  
Hot Isostatic Pressing ◽  
Microstructural Analysis ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
Isostatic Pressing ◽  
High Temperature Synthesis ◽  
Conductive Ceramics

BN-AlN-TiB2 compound conductive ceramics from powder mixtures of BN, Al, and TiB2 was fabricated by self-propagating high temperature synthesis (SHS) and hot isostatic pressing (HIP). The powder mixtures were shaped by isostatic cool pressing at 5-10MPa and the combustion reaction was carried at 100-200 MPa N2 by an ignitor. XRD experiments confirmed that the reaction was complete and only AlN, BN and TiB2 were detected. Optical microscopy as well as SEM with an electron probe microanalysis was used for microstructural analysis and revealed a relatively uniform distribution of particulates. The temperature-dependence and composition-dependence of the electrical resistivity of BN-AlN-TiB2 ceramics were studied. The results showed that the optimum composition was 5-10wt% BN, 30-55wt% Al and 60-40wt% TiB2, and the products had the density of 90% of the theoretical, resistivity of 80-1000 μ⋅cm and bending strength of 100-200 MPa.

Dynamic Compaction and Hot-Isostatic-Pressing of Nickelaluminides

1988 ◽  
Vol 133 ◽  
Author(s):  
O. Arkens ◽  
L. Delaey ◽  
J. de Tavernier ◽  
B. Huybrechts ◽  
L. Buekenhout ◽  
...  
Keyword(s):  
High Temperature ◽  
Hot Isostatic Pressing ◽  
Nickel Aluminides ◽  
Dynamic Compaction ◽  
Temperature Synthesis ◽  
Explosive Compaction ◽  
Isostatic Pressing ◽  
Fine Grained ◽  
High Temperature Synthesis ◽  
Fine Nickel

ABSTRACTExplosive compaction and HIPping of stoichiometric mixtures of Ni and Al (and B) powder is optimized in order to obtain fine grained NiAl− and Ni3Al(+B) intermetallics.Starting from an appropriate mixture of pure fine Ni− and fine Al− (and B) powders fine nickel-aluminides are produced due to a selfpropagation high temperature synthesis during processing. HIPping experiments are done also on spherical Ni-coated Al-powders. The specimens are characterized by metallography and the homogeneity of the final product is controlled by microanalytical methods.

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