Refining performance and recession of Al–TiO2–C–La2O3 refiners

2021 ◽  
Vol 112 (5) ◽  
pp. 359-365
Author(s):  
Xiao-wei Han ◽  
Zong-biao Zhang ◽  
Rui-ying Zhang ◽  
Peng Wang
Keyword(s):  
Raw Materials ◽  
Pure Aluminum ◽  
Grain Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Refining Effect ◽  
Average Grain Size ◽  
Refining Performance ◽  
Commercial Pure Aluminum

Abstract Al–TiO2–C–La2O3 refiners were synthesized by the in-situ exothermic dispersion method using TiO2, C, Al and La2O3 powders as raw materials. Scanning electron microscopy equipped with energy dispersive X-ray spectrometry and X-ray diffraction were used to investigate the microstructures of the Al–TiO2–C–La2O3 refiners. Commercial pure aluminum was refined by the Al–TiO2–C–La2O3 refiners, aimed at investigating refining performance and the resistance to recession. The results show that the Al–TiO2– C–La2O3 refiner with 0.2% La2O3 is composed of α-Al, blocky Al3Ti, dispersive Al2O3 and TiC, which has a better refining effect on commercial pure aluminum than the Al– TiO2–C refiner. The average grain size refined by the above refiner is about 80 μm and it performs better and has a longer refining effect. The grain structure refined by Al–TiO2– C–La2O3 becomes finer within 5 min and remains the same after 120 min, while refined by the Al–TiO2–C refiner the equivalent times are 10 min and 30 min respectively.

Grain Refinement of AZ91D Magnesium Alloy by In Situ Al4C3 Particles

2011 ◽  
Vol 306-307 ◽  
pp. 429-432
Author(s):  
Hui Han ◽  
Hua Ming Miao ◽  
Sheng Fa Liu ◽  
Yang Chen
Keyword(s):  
Magnesium Alloy ◽  
Grain Refinement ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Az91d Magnesium Alloy ◽  
Average Grain Size ◽  
Central Regions ◽  
Heterogeneous Nucleus

Experiments were conducted to fabricate the Al4C3 particles by powder in-situ synthesis process under argon atmosphere and examine the grain refinement of AZ91D magnesium alloy with the addition of 0.6%Al4C3(hereafter in mass fraction,%). By means of X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS), the results show the successful fabrication of Al4C3 particles. After adding 0.6%Al4C3, the average grain size of AZ91D magnesium alloy decreased from 360μm to 243μm. Based on the differential thermal analysis (DTA) results and calculations of the planar disregistry between Al4C3 and α-Mg, Al4C3 particles located in the central regions of magnesium grains can act as the heterogeneous nucleus of primary α-Mg phase.

scholarly journals Investigation of Microstructure of Al-5Ti-0.62C System and Synthesis Mechanism of TiC

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 310 ◽  
Author(s):  
Wanwu Ding ◽  
Taili Chen ◽  
Xiaoyan Zhao ◽  
Yan Cheng ◽  
Xiaoxiong Liu ◽  
...  
Keyword(s):  
Master Alloy ◽  
Pure Aluminum ◽  
Preparation Process ◽  
Synthesis Mechanism ◽  
Microstructure Transformation ◽  
Master Alloys ◽  
Refining Performance ◽  
Commercial Pure Aluminum ◽  
Positive Effect

Al-Ti-C master alloys have been widely investigated by various researchers. However, their refining effectiveness is still severely compromised by the preparation process. In this work, the aluminum melt in-situ reaction was carried out to synthesize the Al-5Ti-0.62C, and its refining performance was estimated. The thermodynamics calculation and differential scanning calorimeter experiment were used to investigate the synthesis mechanism of TiC. Quenching experiment was conducted to explore phase and microstructure transformation of the Al-5Ti-0.62C system. The results show that the main phases of Al-5Ti-0.62C master alloys are α-Al, Al3Ti, and TiC and it has a positive effect on commercial pure aluminum refining. Commercial pure aluminum is completely refined into the fine equiaxed structure by adding 0.3% Al-5Ti-0.62C master alloy. TiC particles mainly distribute in the grain interior and grain boundaries. The excess Ti came from the dissolution of Al3Ti spreading around TiC and finally forming the Ti-rich zone to promote the nucleation of α-Al. The experiments certified that TiC was formed by the reaction between solid C and excess Ti atoms. The main reactions in the Al-5Ti-0.62C system were that solid Al is transferred into liquid Al, and then liquid Al reacted with solid Ti to form the Al3Ti. At last, the release of a lot of heat promotes the formation of TiC which formed by the Ti atoms and solid C.

Synthesis and Characterization of PMMA/MMT Nanocomposites

2012 ◽  
Vol 182-183 ◽  
pp. 249-253
Author(s):  
Jun Qiao ◽  
Jia Wei Shen ◽  
Xiang Hong Huang ◽  
Qian Feng Zhang
Keyword(s):  
Methyl Methacrylate ◽  
Fourier Transformation ◽  
Raw Materials ◽  
Polymerization Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Thermal Stability Of

PMMA/MMT nanocomposites has been prepared by using methyl methacrylate (MMA), montmorillonite (MMT) and ethanolamine as the raw materials via an in-situ free radical polymerization process. The as-prepared nanocomposites were characterized by Fourier transformation infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The results show that the poly(methyl methacrylate) and inorganic montmorillonite have been effectively combined. The structure and thermal stability of the as-prepared nanocomposites are different from the content of MMT in the nanacomposites.

Grain Size and Adhesion Strength of the V8C7 Coatings Produced In Situ

2017 ◽  
Vol 898 ◽  
pp. 1381-1387
Author(s):  
Xin Wang ◽  
Li Sheng Zhong ◽  
Xi Zhang ◽  
Yun Hua Xu ◽  
Hong Wu ◽  
...  
Keyword(s):  
Adhesion Strength ◽  
Vanadium Carbide ◽  
Gray Cast Iron ◽  
Raw Materials ◽  
Average Diameter ◽  
Scratch Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Excellent Adhesion

The vanadium carbide (V8C7) coating was fabricated by in situ reaction which used gray cast iron and vanadium plate as raw materials providing carbon and vanadium sources, respectively. The microstructure, phases, and adhesion strength of V8C7 coating were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and a single scratch test. The XRD results showed that the coating consisted of V8C7 and α-Fe, with the peaks of (222), (400), (440), (622) and (444) of V8C7 phase were confirmed. Moreover, the average diameter (D) of the V8C7 particles in the range of 432~582nm was calculated on the basis of the Scherrer and Halder-Wagner equations. The critical load of interface between V8C7 and substrate was 98.3 N, which implied that the interface of V8C7 coating /substrate had excellent adhesion strength.

Effect of Temperature on the Performance of AlTiC Metal Alloys

2011 ◽  
Vol 339 ◽  
pp. 291-294
Author(s):  
Yong Feng Wang ◽  
Rui Li
Keyword(s):  
Pure Aluminum ◽  
Metal Alloys ◽  
Effect Of Temperature ◽  
Grain Refining ◽  
X Ray Diffraction ◽  
X Ray ◽  
Commercially Pure ◽  
Master Alloys ◽  
Refining Performance ◽  
Al3ti Particle

AlTiC master alloys have been prepared by Contact Reaction Method（CRM）.X-ray diffraction，SEM and EDS were used to analyse the AlTiC master alloys. It showed that morphology and distribution of TiC and Al3Ti particle have correspondingly changed with the transformation of temperature. As a result, the change in morphology and distribution of TiC and Al3Ti particle has considerably affected the gain refining performance of AlTiC master alloys. The result showed that it had excellent grain refining performance for commercially pure aluminum in 800°C.

Study on Synthesis Nanomicrostructures of Zinc Borate (Zn3B6O12•3.5H2O) with Different Morphologies

2011 ◽  
Vol 236-238 ◽  
pp. 1687-1691 ◽  
Author(s):  
Hui Ren ◽  
You Ming Cao ◽  
Zhou Qiao Lei
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Scanning Electron Microscopy ◽  
Raw Materials ◽  
Average Length ◽  
Zinc Borate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The crystal zinc borate (Zn3B6O12·3.5H2O) nano-strips and nano-flakes were successfully prepared by a wet method using boric acid (H3BO3) and Zn(NO3)2·H2O as raw materials in situ aqueous solution, and triethanolamine as the modifying agent. The nano/microstructures and morphologies of the as-obtained samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometer (EDS) and thermogravimetric analysis (TGA). It had been found that the as-prepared materials displayed nanostrips with average length from 100 to 200nm and the thicknesses about 30nm as well as nanoflakes with diameter about 4μm and thickness about several nanometers morphology.

Preparation of TiB2/TiN Nanocomposites by SP

2013 ◽  
Vol 745-746 ◽  
pp. 551-554 ◽  
Author(s):  
Ming Hui Wang ◽  
Hua Jian Li ◽  
Wan Jiang
Keyword(s):  
X Ray Diffraction ◽  
Tem Analysis ◽  
X Ray ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Average Grain Size ◽  
High Resolution Tem ◽  
Spark Plasma ◽  
Xrd Techniques

TiB2/TiN nanocomposites were in-situ fabricated by spark plasma sintering (SPS) technique using Ti and BN powders as starting materials. The phase constituents and microstructures of the samples were analyzed by X-ray diffraction (XRD) techniques, scanning electron microscopy (SEM) and transmission electron microscope (TEM), respectively. The results showed that the average grain size of TiB2 and TiN was 1m and 300nm respectively. Furthermore, high resolution TEM analysis indicated that the as-prepared TiB2/TiN nanocomposites had very clean grain boundaries, and no amorphous phase or oxide layer was observed.

scholarly journals Microstructure and mechanical properties of Ti3(Al,Ga)C2/Al2O3 composites prepared by in situ reactive hot pressing

2020 ◽  
Vol 9 (6) ◽  
pp. 782-790
Author(s):  
Yuan Fang ◽  
Xiaohua Liu ◽  
Yuxia Feng ◽  
Jianfeng Zhu ◽  
Wei Jiang
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Raw Materials ◽  
Second Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reactive Hot Pressing

AbstractIn this study, Ti3(Al,Ga)C2/Al2O3 composites were successfully synthesized by in situ hot pressing at 1350 °C for 2 h using Ti, Al, TiC, and Ga2O3 as raw materials. X-ray diffraction and scanning electron microscopy were used for characterizing the phase identities and microstructures of the sintered composites. The dependence of the Vickers hardness and flexural strength on the Al2O3 content was found to be in single-peak type. Ti3(Al0.6,Ga0.4)C2/10.3vol%Al2O3 composite exhibited significantly improved mechanical properties. Vickers hardness and flexural strength of the composite reached 6.58 GPa and 527.11 MPa, which were 40% and 74% higher than those of Ti3AlC2, respectively. Formation of solid solution and incorporation of second phase of Al2O3 resulted in the opposite influence on the fracture toughness. Finally, the hardening and strengthening mechanisms were discussed in detail.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

1996 ◽  
Vol 54 ◽  
pp. 1020-1021
Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Stoichiometric Composition ◽  
Analytical Electron Microscopy ◽  
Grain Structure ◽  
Solid State Reactions ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

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