Mechanism of Synthesizing Al2O3/Fe-Al Composites with Nano Al2O3 Fibers by In Situ Process

2013 ◽  
Vol 562-565 ◽  
pp. 837-841
Author(s):  
Chen Jing Lu ◽  
Shu Xia Ren ◽  
Jian Lei Wang ◽  
Gang Yu
Keyword(s):  
Phase Composition ◽  
Elemental Composition ◽  
Partial Oxidation ◽  
Aluminum Content ◽  
Sintering Temperature ◽  
Crystal Phase ◽  
In Situ Composite ◽  
Al Content ◽  
Crystal Composition

In-situ composite of Al2O3/Fe-Al with Al2O3 fibers were prepared by partial oxidation of oxygen to Fe powder and Al power, crystal phase composition and elemental composition were analyzed by XRD, NORAN. The results indicated that, the crystal composition is determined by Aluminum content, when the content is enough, FeAl3, Al and Al2O3 will be gain, on the contrary, Fe2Al, FeAl, Fe3Al and Al2O3 will be gain; Al2O3 fibers were synthesized via VLS process, the quantity of Al2O3 fibers increased with the Al content, the whisker’s diameter was improved with increasing of sintering temperature.

Study on TiCp/Al Master Alloy in Magnesium Matrix Composites

2010 ◽  
Vol 97-101 ◽  
pp. 1726-1729
Author(s):  
Xin Ying Teng ◽  
Deng Wei Zhang ◽  
Bo Li
Keyword(s):  
Master Alloy ◽  
Aluminum Content ◽  
Sintering Temperature ◽  
Matrix Material ◽  
Microstructural Characterization ◽  
Magnesium Matrix Composites ◽  
Al Content ◽  
Average Grain Size ◽  
The Matrix ◽  
Tic Particulates

Effects of aluminum content and sintering temperature on microstructures of TiCp/Al master alloy were investigated. The DSC results showed that reaction temperatures of the Al-Ti-C system were influenced by aluminum content. The average grain size of TiCp in the master alloy was 0.5～1μm with 40wt% Al content at 750°C sintering temperature. TiCp/AZ91 composites were fabricated through remelting TiCp/Al master alloy in magnesium alloy. Microstructural characterization of the TiCp/AZ91 composites showed relatively uniform distribution of TiC particulates in the matrix material and the hardness of the composites was improved significantly.

Superplasticity in Nb3Al/Nb In Situ Composites

1999 ◽  
Vol 601 ◽  
Author(s):  
S. Hanada ◽  
W. Fang
Keyword(s):  
Superplastic Deformation ◽  
Grain Boundary Sliding ◽  
Al Alloy ◽  
Two Phase ◽  
Dislocation Glide ◽  
In Situ Composite ◽  
Al Content ◽  
Boundary Sliding ◽  
Equiaxed Grains

AbstractMicrostructures of a binary Nb-15.8at%Al alloy ingot were controlled by isothermal forging and heat treatment to produce equiaxed, fine grains of Nb3Al and Nb solid solution (Nb33). Nb3Al/Nb33 two phase alloy (in-situ composite) is found to exhibit superplasticity especially when one of the constituent phases, Nb33, is supersaturated. During superplastic deformation Nb33 transforms to Nb3Al, and Al content in Nb33 decreases. After superplastic deformation the microstructure consisting of equiaxed grains is left unchanged, although a slight grain growth is observed. It is suggested that stress induced by grain boundary sliding is effectively accommodated through dislocation glide and climb in the soft Nb33

Study of high-pressure sintering behavior of cBN composites starting with cBN–Al mixtures

2008 ◽  
Vol 23 (9) ◽  
pp. 2366-2372 ◽  
Author(s):  
Yongjun Li ◽  
Sicheng Li ◽  
Ran Lv ◽  
Jiaqian Qin ◽  
Jian Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Sintering Temperature ◽  
Cubic Boron Nitride ◽  
Sintering Behavior ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Al Content ◽  
High Pressure Sintering

Cubic boron nitride (cBN) composites starting with cBN–Al mixtures were sintered on WC-16 wt% Co substrates under static high pressure of 5.0 GPa and at temperatures of 800–1400 °C for 30 min. Vickers hardness of the sintered samples increased with increasing cBN content, and the highest hardness of 32.7 GPa was achieved for the cBN–5 wt% Al specimens sintered at 1400 °C. The reactions between cBN and Al started to occur at about 900 °C, and the reaction products strongly depended on the Al content, sintering temperature, and Co diffusion from the substrates according to the x-ray diffraction (XRD) observations. The high pressure and high temperature in situ resistance measurement indicated that the reactions between cBN and Al could be completed in about 90 s when the temperature was higher than ∼1200 °C at high pressure. The cBN composite sintered at 1200 °C from a cBN–15 wt% Al mixture showed the best cutting performance.

Dielectric Properties of Porous Si3N4 Ceramics Prepared by In Situ Cordierite Bonding

2010 ◽  
Vol 434-435 ◽  
pp. 701-704
Author(s):  
Yong Feng Xia ◽  
Yu Ping Zeng ◽  
Dong Liang Jiang
Keyword(s):  
Dielectric Constant ◽  
Phase Composition ◽  
Dielectric Properties ◽  
Sintering Temperature ◽  
Porous Si ◽  
Porous Si3n4 ◽  
Ceramic Process ◽  
Si3n4 Ceramics ◽  
Porous Si3n4 Ceramics

In situ bonding porous silicon nitride (Si3N4) ceramics were fabricated in air using a conventional ceramic process using Si3N4, Al2O3 and MgO as the starting materials. The effects of additives content, sintering temperature and holding time on phase composition, microstructure, dielectric properties and porosity were studied. The porous Si3N4 ceramics were composed of α- Si3N4, SiO2 (cristobalite) and cordierite. Porous Si3N4 ceramics with porosities of 34.12~50.22%, dielectric constant of 2.95~4.45 and dielectric loss of ~0.0025 were obtained.

scholarly journals Mechanical properties and microstructure of Al2O3/TiAl in situ composites doped with Cr and V2O5

2012 ◽  
Vol 44 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Kun Zhang ◽  
Wang Fen ◽  
Jianfeng Zhu ◽  
Huae Wu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Flexural Strength ◽  
Strengthening Mechanism ◽  
Al2o3 Content ◽  
In Situ Composites ◽  
Al2o3 Ceramic ◽  
In Situ Composite

Al2O3/TiAl in situ composites doped with Cr and V2O5 were successfully prepared from Ti, Al, TiO2, Cr and V2O5 by hot pressing. The effect of in situ formed Al2O3 content on the phase composition, microstructure and mechanical properties of Al2O3/TiAl composites were investigated. The results show that the as-synthesized composites mainly consisted of ?-TiAl/?2-Ti3Al matrix and dispersive Al2O3 reinforcing phases. The in situ formed fine Al2O3 ceramic particles mainly disperse on the grain boundaries of TiAl, resulting in refinement of TiAl matrix, which improves the mechanical properties of the Al2O3/TiAl in situ composite. The composite with 7.54 at.% Al2O3 possesses the maximum flexural strength and fracture toughness of 335.38 MPa and 5.39 MPa m1/2, respectively. The strengthening mechanism was also discussed in detail.

Microstructure and phase composition of the Nb-Si based in-situ composite from plasma spheroidized powder

2020 ◽  
Vol 30 ◽  
pp. 545-548
Author(s):  
Ivan Goncharov ◽  
Liliya Hisamova ◽  
Liana Mustafaeva ◽  
Nikolay Razumov ◽  
Tagir Makhmutov ◽  
...  
Keyword(s):  
Phase Composition ◽  
In Situ Composite ◽  
Spheroidized Powder

Effect of spark plasma sintering temperature on structure and phase composition of Ti-Al-Nb-based alloys

2017 ◽  
Vol 59 (11-12) ◽  
pp. 1033-1036 ◽  
Author(s):  
Sherzod Kurbanbekov ◽  
Mazhyn Skakov ◽  
Viktor Baklanov ◽  
Batyrzhan Karakozov
Keyword(s):  
Phase Composition ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Plasma Sintering ◽  
Spark Plasma

scholarly journals The Influence of Aluminum Content on Oxidation Resistance of New-Generation ODS Alloy at 1200 °C

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1478 ◽  
Author(s):  
Luděk Stratil ◽  
Vít Horník ◽  
Petr Dymáček ◽  
Pavla Roupcová ◽  
Jiří Svoboda
Keyword(s):  
Oxidation Resistance ◽  
Cross Sections ◽  
Aluminum Content ◽  
Energy Dispersive Spectrometer ◽  
Oxide Dispersion Strengthened ◽  
Xrd Analysis ◽  
Al Content ◽  
Α Al2o3 ◽  
New Generation ◽  
Ods Alloy

The aim of the paper is to evaluate the effect of aluminum content on the oxidation resistance of new-generation of oxide dispersion strengthened (ODS) alloy at 1200 °C. Three grades of the alloy of chemical composition Fe-15Cr-xAl-4Y2O3 with different Al contents x = 0.3 wt.%, 2.0 wt.% and 5.5 wt.% are prepared by mechanical alloying. The alloys are consolidated by high temperature rolling followed by heat treatment. To study the oxidation resistance the samples are isothermally aged in the air for 1 h, 4 h, 16 h and 64 h at 1200 °C. The oxidation kinetics, composition and formation mechanism of the oxide layers are analyzed. The weight gain of prepared steels is estimated. The kinetics of oxidation is studied on metallographic cross-sections of the exposed samples by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) analysis. The oxides on the surfaces are identified by X‑ray diffraction (XRD) analysis. The Al content significantly enhances the oxidation resistance of the alloy. For a sufficiently high Al content in the alloy a compact oxide layer of α‑Al2O3 on the surface is formed, which significantly suppresses further oxidation process.

scholarly journals Study on Microstructure and In Situ Tensile Deformation Behavior of Fe-25Mn-xAl-8Ni-C Alloy Prepared by Vacuum Arc Melting

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 814
Author(s):  
Yaping Bai ◽  
Meng Li ◽  
Chao Cheng ◽  
Jianping Li ◽  
Yongchun Guo ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Deformation Behavior ◽  
Tensile Deformation ◽  
Austenite Phase ◽  
Vacuum Arc ◽  
Al Content ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Tensile Deformation Behavior

In this study, Fe-25Mn-xAl-8Ni-C alloys (x = 10 wt.%, 11 wt.%, 12 wt.%, 13 wt.%) were prepared by a vacuum arc melting method, and the microstructure of this series of alloys and the in situ tensile deformation behavior were studied. The results showed that Fe-25Mn-xAl-8Ni-C alloys mainly contained austenite phase with a small amount of NiAl compound. With the content of Al increasing, the amount of austenite decreased while the amount of NiAl compound increased. When the Al content increased to 12 wt.%, the interface between austenite and NiAl compound and austenitic internal started to precipitate k-carbide phase. In situ tensile results also showed that as the content of Al increased, the alloy elongation decreased gradually, and the tensile strength first increased and then decreased. When the Al content was up to 11 wt.%, the elongation and tensile strength were 2.6% and 702.5 MPa, respectively; the results of in situ tensile dynamic observations show that during the process of stretching, austenite deformed first, and crack initiation mainly occurred at the interface between austenite and NiAl compound, and propagated along the interface, resulting in fracture of the alloy.

The study of crystal-phase composition and pore structure for Dicaoqing-Zisha compared with porcelain and pottery

2020 ◽  
Author(s):  
Chunrui Yang ◽  
Jianyi Kong ◽  
Jiajing Yang ◽  
Chengliang Chu ◽  
Xingdong Wang ◽  
...  
Keyword(s):  
Phase Composition ◽  
Pore Structure ◽  
Crystal Phase
Sign in / Sign up

Export Citation Format

Share Document