In situ synthesis of NbB2–NbC composite powders by milling-assisted carbothermal reduction of oxide raw materials

2015 ◽  
Vol 26 (4) ◽  
pp. 1200-1209 ◽  
Author(s):  
Özge Balcı ◽  
Duygu Ağaoğulları ◽  
Didem Ovalı ◽  
M. Lütfi Öveçoğlu ◽  
İsmail Duman
Keyword(s):  
Carbothermal Reduction ◽  
Raw Materials ◽  
In Situ Synthesis ◽  
Composite Powders

In Situ Synthesis of ZrB2–SiC Composite Powders by Carbothermal Reduction Method

2018 ◽  
pp. 101-107
Author(s):  
Bingying Xie ◽  
Jincheng Yu ◽  
Yujun Zhang ◽  
Hongyu Gong ◽  
Xiao Lin ◽  
...  
Keyword(s):  
Carbothermal Reduction ◽  
Reduction Method ◽  
In Situ Synthesis ◽  
Composite Powders ◽  
Carbothermal Reduction Method

Mechanical Properties of Hot-Pressed B4C-TiB2 Composites Synthesized from B4C-TiO2 and B4C-TiC

2021 ◽  
Vol 902 ◽  
pp. 81-86
Author(s):  
Shu Mao Zhao ◽  
Ling Ran Zhao
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Volume Fraction ◽  
Raw Materials ◽  
Ceramic Composites ◽  
In Situ Synthesis ◽  
Second Phase ◽  
Pressing Method ◽  
The One

In this study, B4C-TiB2 ceramic composites were manufactured by hot pressing method. The raw materials for the in-situ synthesis of TiB2 were TiO2 and TiC. After being sintered at 1900°C for 60min under a pressure of 30MPa, compact composites samples with a TiB2 volume fraction range from 0 to 11.05% were prepared. The relative density, fracture toughness and flexural strength of different sample were tested. Microstructures on the fracture surface were studied by SEM. The result shows that B4C-TiB2 ceramic composites sintered from B4C-TiC had a better mechanical property than the one sintered from B4C-TiO2. When the content of TiB2 (reacted from TiC) was 11.05vol.%, the strength and toughness of B4C-TiB2 ceramics can reach 598MPa and 6.45MPa·m1/2. The toughening mechanisms of B4C-TiB2 composites include micro-crack toughening and energy consumption by the pulling out process of second phase.

In Situ Synthesis of Ultrafine ZrB2–SiC Composite Powders and the Pressureless Sintering Behaviors

2008 ◽  
Vol 91 (4) ◽  
pp. 1372-1376 ◽  
Author(s):  
Yongjie Yan ◽  
Hui Zhang ◽  
Zhengren Huang ◽  
Jianxue Liu ◽  
Dongliang Jiang
Keyword(s):  
In Situ Synthesis ◽  
Pressureless Sintering ◽  
Composite Powders

One-step in situ synthesis and characterization of W18O49@carbon coaxial nanocables

2009 ◽  
Vol 24 (5) ◽  
pp. 1833-1841 ◽  
Author(s):  
Yuqin Zhou ◽  
Yong Zhang ◽  
Ruying Li ◽  
Mei Cai ◽  
Xueliang Sun
Keyword(s):  
Raw Materials ◽  
Tungsten Powder ◽  
Carbon Sources ◽  
Chemical Vapor ◽  
Deposition Process ◽  
In Situ Synthesis ◽  
X Ray ◽  
Coaxial Nanocables ◽  
Catalyst Systems

We demonstrate here in situ synthesis of bulk yield W18O49@carbon coaxial nanocables based on an easily controlled chemical vapor deposition process at relatively low temperature (760 °C) using metallic tungsten powder and ethylene (C2H4) as the raw materials. Transmission electron microscope (TEM), energy dispersive x-ray (EDX), and x-ray diffraction (XRD) analyses indicate that the resultant nanostructures are composed of single-crystalline W18O49 nanowires, coaxially covered with amorphous carbon walls. A vapor–solid (VS) mechanism is proposed to interpret the formation of the nanocables. The effect of carbon sources on the nanocable growth was investigated. The results revealed that the introduction of carbon species not only causes the production of W18O49@C nanocable structures, but also obviously modulates growth behaviors and core/shell diameter ratio of the nanocables. The obtained nanocables may find great applications in catalyst systems and optical and electronic nanodevices because of their enhanced surface properties, as well as in high chemical stability.

In Situ Synthesis of CNTs/Mg Composite Powders by CVD at Low Temperatures

2012 ◽  
Vol 588-589 ◽  
pp. 1681-1684
Author(s):  
Fu Jun Sun ◽  
Chun Sheng Shi ◽  
En Zuo Liu ◽  
Chun Nian He ◽  
Nai Qin Zhao
Keyword(s):  
Mechanical Property ◽  
Carbon Nanotubes ◽  
Vapor Deposition ◽  
Low Temperatures ◽  
Chemical Vapor ◽  
In Situ Synthesis ◽  
Composite Powders ◽  
Co Catalyst ◽  
Synthesis Of Carbon Nanotubes

The emphasis of this study was in-situ synthesis of carbon nanotubes (CNTs) on Mg matrix at 480°C. The process involves homogeneous deposition of Co catalyst onto Mg by deposition-precipitation route with low Co content (1.0 wt.%) and in situ synthesis of CNTs by chemical vapor deposition. The morphologies and microstructure of the as-obtained CNTs/Mg composite powders was characterized by SEM, TEM, Raman spectrum, and XRD. The results indicated that CNTs were well graphitized and uniformly distributed on the surface of Mg powders, which would be beneficial to the mechanical property of CNTs/Mg composites.

Synthesis of Ternary Machinable Al2O3/Ti2AlC Composites by High Energy Milling and In Situ Hot-Pressing Method

2010 ◽  
Vol 658 ◽  
pp. 169-172 ◽  
Author(s):  
Fen Wang ◽  
Bo Bo Liu ◽  
Jian Feng Zhu ◽  
Ya Ling Li
Keyword(s):  
Hot Pressing ◽  
Raw Materials ◽  
High Energy ◽  
Milling Process ◽  
Vacuum Furnace ◽  
Composite Powders ◽  
Pressing Method ◽  
Fine Grained ◽  
High Energy Milling

Al2O3/Ti2AlC composites were synthesized by high energy milling and hot-pressing at 1200°C in a vacuum furnace with a pressure of 4.8×10-2 Pa, using Ti, Al and C powder as raw materials. The effect of sintering temperature on the reactions, phase composition and microstructure of the synthesized products were investigated. The results show that the TiC and TiAl intermetallics composite powders were synthesized during the milling process. After the hot pressing, Ti2AlC phase was formed by the reaction between TiC and TiAl. A small amount of Al2O3 was also produced because of the oxidation of Al in the hot press process, which formed Al2O3/Ti2AlC composite together with the Ti2AlC at 1200°C. The fine grained Al2O3 particles disperse within Ti2AlC uniformly, which play a important role to strengthen Ti2AlC matrix, resulting in the increase of flexural strength and fracture toughness from 250 to 275.4MPa, 9.8 to 10.5MPa•m1/2, respectively.

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