scholarly journals Pressureless sintering of HfB2-based ceramics as control rod materials: Synergistic effects of the sintering additive and solid solution

2021 ◽  
Author(s):  
Jia-Xiang Xue ◽  
Rui Shu ◽  
Ye-Hong Liao ◽  
Qi-Sen Ren
Keyword(s):  
Solid Solution ◽  
Synergistic Effects ◽  
Pressureless Sintering ◽  
Control Rod ◽  
Sintering Additive

Characterization of Ti-based solid solution cermets prepared by mechanically induced self-sustained reaction and subsequent pressureless sintering

2014 ◽  
Vol 583 ◽  
pp. 523-529 ◽  
Author(s):  
Xiao Chen ◽  
Weihao Xiong ◽  
Zhenhua Yao ◽  
Guopeng Zhang ◽  
Shan Chen ◽  
...  
Keyword(s):  
Solid Solution ◽  
Pressureless Sintering

Pressureless sintering of boron carbide with Cr3C2 as sintering additive

2014 ◽  
Vol 34 (5) ◽  
pp. 1073-1081 ◽  
Author(s):  
Xiaoguang Li ◽  
Dongliang Jiang ◽  
Jingxian Zhang ◽  
Qingling Lin ◽  
Zhongming Chen ◽  
...  
Keyword(s):  
Boron Carbide ◽  
Pressureless Sintering ◽  
Sintering Additive

Colossal thermoelectric enhancement in Cu2+xZn1−xSnS4 solid solution by local disordering of crystal lattice and multi-scale defect engineering

2020 ◽  
Vol 8 (21) ◽  
pp. 10909-10916 ◽  
Author(s):  
Qinghui Jiang ◽  
Haixue Yan ◽  
Yuanhua Lin ◽  
Yang Shen ◽  
Junyou Yang ◽  
...  
Keyword(s):  
Solid Solution ◽  
Crystal Lattice ◽  
Synergistic Effects ◽  
Hot Forging ◽  
Electric Transport ◽  
Defect Engineering ◽  
Length Scales ◽  
Multi Scale ◽  
Thermal Conductivities

Synergistic effects of Cu self-doping and hot forging of Cu2ZnSnS4 realize the decoupling of thermal and electric transport. And hot forging produces defects on different length scales and effectively optimize the electric and thermal conductivities.

Creep Behaviour of Si3N4 Ceramics Sintered with RE2O3

2006 ◽  
Vol 514-516 ◽  
pp. 759-763
Author(s):  
Claudinei dos Santos ◽  
Kurt Strecker ◽  
Francisco Piorino Neto ◽  
Cosme Roberto Moreira Silva ◽  
Flávia A. Almeida ◽  
...  
Keyword(s):  
Solid Solution ◽  
Relative Density ◽  
Creep Behaviour ◽  
Rare Earth Oxide ◽  
Grain Boundary Sliding ◽  
Creep Tests ◽  
Sintering Additive ◽  
Compressive Stresses ◽  
Oxide Solid Solution ◽  
Boundary Sliding

The objective of this work was to evaluate the creep behaviour of Si3N4 based ceramics obtained by uniaxial hot-pressing. As sintering additive, an yttrium-rare earth oxide solid solution, designed RE2O3, that shows similar characteristics to pure Y2O3, was used. Samples were sintered using high-purity α-Si3N4 powder, with additive mixtures based on RE2O3/Al2O3 or RE2O3/AlN, at 5 and 20 vol.%, respectively. The sintered samples were characterized by X-ray diffractometry, scanning electron microscopy and density. Specimens of 3x3x6 mm3 were submitted to creep tests, under compressive stresses between 100 and 350 MPa at temperatures ranging from 1250 to 13750C in air. Samples with RE2O3/Al2O3 showed β-Si3N4 as crystalline phase, with grains of high aspect ratio, and a relative density around 99% of the theoretical density. The Si3N4/RE2O3/AlN samples presented α-Si3N4 solid solution, designed α-SiAlON, with a more equiaxed microstructure and slightly lower relative density (96-98%). The results of creep tests indicated that these ceramics containing α-SiAlON are the more creep resistant, with steady-state creep rates around 10-4 h-1, with stress exponents (n) in the range 0.67-2.53, indicating grain boundary sliding as the main creep mechanism.

Properties of Pressureless Sintered SiC-TiB2 Composites

2010 ◽  
Vol 177 ◽  
pp. 369-372 ◽  
Author(s):  
Yu Hong Chen ◽  
Liang Jiang ◽  
Xue Hong Jia
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Pressureless Sintering ◽  
Composite Ceramics ◽  
Sem Images ◽  
Sintering Additive ◽  
Xrd Patterns ◽  
New Phase ◽  
Full Densification ◽  
Sic Particle

Silicon carbide( SiC) – titanium diboride (TiB2) composite was prepared with boron (B) and carbon (C) as sintering additive via pressureless sintering at 2180°C. The density of sintered samples achieved 96% of full densification. The mechanical properties and electrical conductivity of composite ceramics with different SiC content were researched. The results showed that with the increasing of SiC content the hardness and electrical resistivity of composites decreased, while the strength increased. Although the XRD patterns of sintered samples showed that non new phase was produced, SEM images showed that SiC particle enlarged and surrounded by TiB2 grain during sintering. In this case the fracture mode was intergranular fracture.

scholarly journals Strengthening from Cu Addition in 0.2C-(1-2)Mn Steels during Tempering

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 247 ◽  
Author(s):  
Jaromir Dlouhy ◽  
Pavel Podany ◽  
Jan Dzugan
Keyword(s):  
Solid Solution ◽  
Tensile Testing ◽  
Synergistic Effects ◽  
Precipitation Strengthening ◽  
Subsequent Tempering

The strengthening effects of Cu and Mn were studied in steels, which contained 0.2% C and were micro-alloyed with B and Ti. The experimental steels were austenitized and quenched in order to take Mn and Cu into solid solution. The subsequent tempering of martensitic structures resulted in higher strengths in the materials alloyed with Cu than in the steel without Cu addition. Tensile testing and metallographic analyses were performed. The kinetics and magnitude of precipitation strengthening were measured for different tempering temperatures and times. Presumed synergistic effects between Cu precipitation strengthening and higher levels of Mn were observed.

Novel precursor-derived Al–C–N–(O)-based ceramic additive for the low-temperature pressureless sintering of silicon nitride

2008 ◽  
Vol 23 (6) ◽  
pp. 1713-1721
Author(s):  
Sea-Hoon Lee ◽  
Markus Weinmann ◽  
Peter Gerstel ◽  
Georg Rixecker ◽  
Sung-Churl Choi ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Chemical Composition ◽  
Low Temperature ◽  
Homogeneous Distribution ◽  
Pressureless Sintering ◽  
Sintering Additive ◽  
Silicon Carbide Particles ◽  
Trimethylamine Alane ◽  
Carbide Particles

A polymer, which by pyrolysis transforms into Al–C–N–(O) ceramics, was synthesized from trimethylamine alane and cyan amide, and its applicability as a sintering additive for Si3N4 was investigated. Si3N4 powders were mixed with the precursor by treatment with organic slurries of the precursor to induce the homogeneous distribution of the additive. The green-bodies were pretreated in air or NH3 at 800 °C to control the chemical composition of the additive, through which the densification of Si3N4 could be improved. Dense samples with very fine grains (<2 μm) were obtained after sintering at 1600 °C in 0.1 MPa N2. Besides silicon nitride, submicrometer silicon carbide particles were observed in the samples, indicating that this procedure (i.e., the use of this novel sintering additive) also allows for the fabrication of SiC–Si3N4 composites.

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