Porous TiN Ceramics Fabricated by Carbothermal Reduction Method

2013 ◽  
Vol 745-746 ◽  
pp. 667-672 ◽  
Author(s):  
Yuan Lu ◽  
Jian Feng Yang ◽  
Zhi Liang Chen ◽  
Jian Jun Han ◽  
Jing Jing Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Pore Structure ◽  
Carbothermal Reduction ◽  
Xrd Analysis ◽  
Linear Shrinkage ◽  
Reduction Reaction ◽  
Sem Analysis ◽  
High Porosity ◽  
Microstructure And Mechanical Properties

Porous TiN ceramics with high porosity and uniform pore structure was prepared following the carbothermal reduction reaction between TiO2 and carbon. Influences of sintering additives and particle size of TiO2 on the microstructure and mechanical properties of porous TiN ceramics were investigated. Microstructure and mechanical properties of porous TiN ceramics were studied by XRD, SEM and three-point bending measurement. XRD analysis proved that the TiN phase has completely formed after reaction. In addition, SEM analysis showed that the resultant porous TiN ceramics were composed of fine grains with uniform pore structure. The addition of La2O3 not only accelerated the densification of porous TiN ceramics, but also decreased the porosity and increased the flexural strength. With a decrease in TiO2 particle size, the linear shrinkage increased and the porosity decreased accordingly.

Porous AlN Ceramics Fabricated by Carbothermal Reduction

2014 ◽  
Vol 788 ◽  
pp. 627-631
Author(s):  
Yuan Lu ◽  
Jing Long Li ◽  
Jian Feng Yang ◽  
Peng Li
Keyword(s):  
Mechanical Properties ◽  
Carbothermal Reduction ◽  
Glass Phase ◽  
Sintering Temperature ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
High Porosity ◽  
Sintering Additives ◽  
Fine Microstructure ◽  
Complete Formation

A new method for preparing porous AlN ceramics with high porosity had been developed by carbothermal reduction of die-pressed green bodies composed of alumina, carbon, sintering additives and AlN seeds. The influences of sintering additives and sintering temperature on the microstructure and mechanical properties of porous AlN ceramics were investigated. XRD analysis proved that complete formation of AlN phase except for minor of glass phase. SEM analysis showed that the resultant porous AlN ceramics occupied fine microstructure and a uniform pore structure. Porous AlN ceramics with a porosity of 41~66% and a strength of 2.7~ 51.8 MPa were obtained.

Fabrication of Porous Silicon Nitride with High Porosity

2007 ◽  
Vol 336-338 ◽  
pp. 1105-1108 ◽  
Author(s):  
Shao Yun Shan ◽  
Jian Feng Yang ◽  
Ji Qiang Gao ◽  
Wen Hui Zhang ◽  
Zhi Hao Jin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Xrd Analysis ◽  
Reduction Reaction ◽  
Sem Analysis ◽  
High Porosity ◽  
Sintering Additive ◽  
Fine Microstructure ◽  
Porous Si3n4 ◽  
Si3n4 Ceramics ◽  
Porous Si3n4 Ceramics

In this study, porous Si3N4 ceramics were fabricated by carbothermal reduction reaction between silicon dioxide and carbon. The influences of different starting powders and sintering additives on microstructure and mechanical properties were investigated. XRD analysis demonstrated the formation of single-phase β-Si3N4 except for glass phase and minor of α-Si3N4 phase. SEM analysis showed that the resultant porous Si3N4 ceramics occupied fine microstructure and uniform pore structure. The samples with fine starting powder showed fine, high aspect ratio of β-Si3N4 grains and good mechanical properties. The addition of Al2O3 accelerated the densification of porous Si3N4 ceramics. With an increasing in the sintering additive content, the porosity decreased, the flexural strength increased.

Effects of Welding Wire Composition on Microstructure and Mechanical Properties of Welded Joint in Al-Mg-Si Alloy

2022 ◽  
Vol 905 ◽  
pp. 44-50
Author(s):  
Li Wang ◽  
Ya Ya Zheng ◽  
Shi Hu Hu
Keyword(s):  
Mechanical Properties ◽  
Fusion Zone ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
Weld Zone ◽  
Xrd Analysis ◽  
Metallographic Analysis ◽  
Strengthening Effect ◽  
Welding Wire ◽  
Microstructure And Mechanical Properties

The effects of welding wire composition on microstructure and mechanical properties of welded joint in Al-Mg-Si alloy were studied by electrochemical test, X-ray diffraction (XRD) analysis and metallographic analysis. The results show that the weld zone is composed of coarse columnar dendrites and fine equated grains. Recrystallized grains are observed in the fusion zone, and the microstructure in the heat affected zone is coarsened by welding heat. The hardness curve of welded joint is like W-shaped, the highest hardness point appears near the fusion zone, and the lowest hardness point is in the heat affected zone. The main second phases of welded joints are: matrix α-Al, Mg2Si, AlMnSi, elemental Si and SiO2. The addition of rare earth in welding wire can refine the grain in weld zone obviously, produce fine grain strengthening effect, and improve the electrochemical performance of weld.

scholarly journals Effect of Intercritical Annealing and Austempering on the Microstructure and Mechanical Properties of a High Silicon Manganese Steel

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1448 ◽  
Author(s):  
Mattia Franceschi ◽  
Luca Pezzato ◽  
Claudio Gennari ◽  
Alberto Fabrizi ◽  
Marina Polyakova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Intercritical Annealing ◽  
High Strength ◽  
Xrd Analysis ◽  
Tensile Tests ◽  
Manganese Steel ◽  
Microstructure And Mechanical Properties ◽  
Martensitic Microstructure ◽  
Steel Grades ◽  
High Silicon

High Silicon Austempered steels (AHSS) are materials of great interest due to their excellent combination of high strength, ductility, toughness, and limited costs. These steel grades are characterized by a microstructure consisting of ferrite and bainite, accompanied by a high quantity retained austenite (RA). The aim of this study is to analyze the effect of an innovative heat treatment, consisting of intercritical annealing at 780 °C and austempering at 400 °C for 30 min, on the microstructure and mechanical properties of a novel high silicon steel (0.43C-3.26Si-2.72Mn wt.%). The microstructure was characterized by optical and electron microscopy and XRD analysis. Hardness and tensile tests were performed. A multiphase ferritic-martensitic microstructure was obtained. A hardness of 426 HV and a tensile strength of 1650 MPa were measured, with an elongation of 4.5%. The results were compared with those ones obtained with annealing and Q&T treatments.

Nano Titania Reinforced Limestone Cement: Physico-Mechanical Investgation

2018 ◽  
Vol 786 ◽  
pp. 248-257
Author(s):  
Mohmoud A. Abuelseoud ◽  
Asmaa S. Hamouda ◽  
Ibrahim M. Ismail ◽  
M.A. El-Sheikh
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Physical And Mechanical Properties ◽  
Sem Analysis ◽  
Cement Clinker ◽  
Titanium Silicate ◽  
Cement Pastes ◽  
Limestone Cement

Studying physical and mechanical properties of limestone cement pastes blended by TiO2 nanoparticles (i.e., particle size less than 100 nm). Three mixes are prepared for this study (5.00, 10.00 and 25.00 wt. % of limestone) partially replaced cement/clinker by TiO2 nanoparticles. Fillers are carefully selected which reinforcing cement workability or water retention they could be inert or have slightly hydraulic properties. Limestone is most common filler that fills the pores between cement particles due to the formation of monocarboaluminate, while nanoparticles increase the hydration C-S-H gel product and calcium titanium silicate which hardened the cement pastes. Nanoparticles show a great effect in reinforcing the mechanical strength of cement pastes due to the fact that TiO2-nanoparticles act as active nuclei site forming C-S-H gel observed as honeycomb-like plus improving cement to water demined (W/C) ratio. SEM analysis proves that the morphology of cement structure is well arranged and compacted.

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