EFFECT OF MILLING PARAMETERS ON MICROSTRUCTURE OF Ti/Al COMPOSITE POWDER PRODUCED BY DISCUS MILLING

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4679-4684 ◽  
Author(s):  
S. RAYNOVA ◽  
P. CAO ◽  
B. GABBITAS ◽  
D. ZHANG
Keyword(s):  
Composite Powder ◽  
Single Phase ◽  
Vapour Deposition ◽  
Bulk Material ◽  
Control Agent ◽  
Powder Particle Size ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Pvd Coating ◽  
Al Composite

The motivation of this research is to develop a process for producing Ti/Al composite powders that enable synthesis of a single-phase TiAl intermetallic bulk material, which is then used as a target for physical vapour deposition (PVD) coating. This study reports the effects of milling time, amount of process control agent (PCA) added as well as the powder-to-medium ratio on the microstructure of the Ti/Al composite powder. Optical microscopy and scanning electron microscopy (SEM) were used to evaluate the level of mixing and the resulting powder particle size. X-ray diffraction analysis and differential thermal analysis were used for determining the phase constituents and the solid state reaction temperature of the as-milled powders.

scholarly journals Influence of Phase Composition on Sintered Microstructure of Combustion Synthesized Oxides

2007 ◽  
Vol 2007 ◽  
pp. 1-5
Author(s):  
Ibram Ganesh ◽  
J. M. F. Ferreira
Keyword(s):  
Composite Powder ◽  
Single Phase ◽  
Absorption Capacity ◽  
Synthesis Methods ◽  
Water Absorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Point Bend Test ◽  
Three Point Bend Test ◽  
Point Bend

The effects of powders synthesis methods (urea-combustion synthesis (CS) and conventional solid-state (SS) reaction) on the sintering ability, microstructural features, and mechanical properties ofAl2O3,MgAl2O4spinel, and 20 wt.% ZrO2–MgAl2O4upon sintering at 1625C∘were investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), relative density (RD), apparent porosity and water absorption capacity, hardness, fracture toughness, and three-point bend test studies revealed the superior sintering ability of CS ZrO2-MgAl2O4composite powder as compared with one prepared by SS reaction. In contrast, single-phase powders obtained by SS reaction exhibit superior sintering ability over CS synthesized ones. The reasons for differences observed are discussed along this paper.

B4C/5083 Al Composite Prepared by Cryomilling

2011 ◽  
Vol 233-235 ◽  
pp. 1825-1829
Author(s):  
Bin Hao ◽  
Ji Shan Zhang ◽  
Da Cheng Liu
Keyword(s):  
Composite Powder ◽  
Milling Time ◽  
Hot Extrusion ◽  
Coarse Grained ◽  
Coarse Grain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Blended Powder ◽  
Al Composite ◽  
B4c Particles

In the present investigation, the composite powder with 20wt.% particulate B4C and 80wt.% nanocrystalline 5083 Al was fabricated using mechanically milling at cryogenic temperature (cryomilling). After this, the cryomilled composite powder was homogeneously blended with an equal amount of unmilled coarse-grained 5083 Al. The blended powder was consolidated with hot-pressing at 500°C, followed by hot extrusion at 410°C. The consolidated composite consists of 10wt.% B4C, 50wt.% coarse grain 5083 Al and the balance nanocrystalline 5083 Al. The microstructure evolution of the composite during cryomilling and consolidation was investigated by X-ray diffraction (XRD), optical microscopy (OM) and scanning electron microscopy (SEM). The results show that the particle size of the cryomilled composite powder became smaller and then bigger with milling time longer. This demonstrates the course rely mainly on broken first, and then rely mainly on cold welding with milling time longer. B4C particles can be distributed in 5083 Al matrix uniformly. In addition, the presence of oxygen and nitrogen in cryomilled powders has been demonstrated in this paper.

Studies on Microstructure of Cu-SiC Compounds by Mechanical Alloying

2015 ◽  
Vol 1089 ◽  
pp. 76-79
Author(s):  
Liang Chen ◽  
Zhan Wen He
Keyword(s):  
Particle Size ◽  
Lattice Constant ◽  
Ball Mill ◽  
Composite Powder ◽  
High Energy ◽  
Powder Particle Size ◽  
Micro Structure ◽  
Composite Powders ◽  
High Energy Ball Mill ◽  
Energy Ball

Cu - SiC composite powders were discussed in this paper the microstructure after ball mill, through to the ball mill after Cu-SiC composite powder particle size and lattice constant analysis, confirmed the high-energy ball mill to Cu-SiC micro structure of the binary alloy. The experimental results show that the ball mill after 20 h, Cu particle size has a larger extent reduce after high-energy ball mill and SiC lattice constant increase.

Synthesis of Al2O3/AlN composite powders by plasma processed Al2O3with various additives

2004 ◽  
Vol 19 (5) ◽  
pp. 1356-1363 ◽  
Author(s):  
F.Y.C. Boey ◽  
X.L. Zhao ◽  
A.I.Y. Tok
Keyword(s):  
Reaction Mechanism ◽  
Composite Powder ◽  
X Ray Diffraction ◽  
Minor Phase ◽  
Composite Powders ◽  
Major Phase ◽  
X Ray ◽  
Different Types ◽  
Novel Method ◽  
Direct Nitridation

A novel method was developed to produce Al2O3/AlN composite powders. The composite powders were synthesized by the direct nitridation of Al2O3using various additives by plasma processed with two different types of gas (Ar/N2and N2plasma). The effects of these two different plasma gases and additives on the formation of the Al2O3/AlN composites were studied. The x-ray diffraction results in the composite powders showed that the cubic AlN was converted to the major phase while transient γ–Al2O3was the minor phase when the composite powder was fully melted using nitrogen as the sole working gas. In contrast, the main phase was still α–Al2O3when the composite powder was not well melted using the mixture of argon and nitrogen as the working gas. Carbon was found as an effective conversion additive to increase the cubic AlN of this composite powder up to 49 vol%. The reaction mechanism of forming this composite powder was also analyzed.

Synthesis of In2Se3/CuSe Composite Powder by Solvothermal Method

2012 ◽  
Vol 512-515 ◽  
pp. 211-214
Author(s):  
J. Gao ◽  
Z.G. Zou ◽  
F. Long ◽  
C.Y. Xie ◽  
S.S. Chi
Keyword(s):  
Atmospheric Pressure ◽  
Composite Powder ◽  
Solvothermal Method ◽  
Ammonium Bromide ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
X Ray ◽  
Average Size ◽  
Scanning Electron

The In2Se3/CuSe composite powders with the size in the range of 2-8µm for solar cell were successfully synthesized via using relatively simple solvothermal method at atmospheric pressure by the reaction between InCI3.4H2O, CuCI2.2H2O and Selenious acid and hydrazine hydrate in ethylene glycol.The influences of reaction temperature, reaction time, concentration of solution on the phase and morphology of In2Se3/CuSe composite powders were investigated. The phase and morphology of the products hSubscript textave been well studied by X-ray diffraction (XRD)and scanning electron microscope (SSubscript textEM) techniques.The study revealed that under the conditions of solvothermal method at atmospheric pressure, relative pure In2Se3 and CuSe powder were synthesized at temperatures of 160°C and 100°C respectively. The In2Se3/CuSe of irregular flake composite powders with the average size of 2-8µm had been obtained.The morphology of the products can be controlled by adding different kinds of surfactants such as PVP (Polyvinylpyrrolidone), CTAB (Hexadecyl trimethyl ammonium Bromide) and so on.

Factors Affecting the Separation of Ti-Al Alloy in the TiPro Process

2013 ◽  
Vol 551 ◽  
pp. 44-54
Author(s):  
Kenneth Sichone ◽  
De Liang Zhang ◽  
Stella Raynova
Keyword(s):  
Powder Particle ◽  
Composite Powder ◽  
Al Alloy ◽  
Composite Powders ◽  
Factors Affecting ◽  
Al Composite ◽  
Al2o3 Phase ◽  
The University ◽  
Solid Liquid ◽  
Solid Liquid Separation

Abstract This paper presents and discusses the factors influencing the yield of Ti-Al alloy in the TiPro process which is a process developed at the University of Waikato for producing titanium alloy powders by mechanically activating Al/TiO2 powder mixtures and subsequently preheating the resultant composite powder in order to ignite a combustion synthesis reaction and separate the liquid Ti-Al alloy by extrusion. In this study, TiO2/Al composite powders with different powder particle microstructures have been produced and used to study the effects of starting composite powder particle microstructure on the solid/liquid separation of TiAl from solid Al2O3 by extrusion. Results obtained so far indicate that maximizing the time the Ti-Al alloy phase is maintained in the liquid state after the reaction between TiO2 and Al is one of the critical factors to increase the yield of Ti-Al alloy produced through the separation of liquid Ti-Al from the solid Al2O3 phase by extruding the mixture of liquid Ti-Al and Al2O3 formed through reactions and heating.

Raman And Fluorescence Spectra Observed in Laser Microprobe Measurements of Several Compositions in the Ln-Ba-Cu-O System

1990 ◽  
Vol 48 (2) ◽  
pp. 278-279
Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng
Keyword(s):  
Fluorescence Spectra ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Raman Microprobe ◽  
Methods Of Synthesis ◽  
Compositional Homogeneity ◽  
Processing Techniques

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.

Observation of pseudo 10-fold symmetry in the ordered iron-zinc delta phase

1992 ◽  
Vol 50 (1) ◽  
pp. 36-37
Author(s):  
L. A. Giannuzzi ◽  
A. S. Ramani ◽  
P. R. Howell ◽  
H. W. Pickering ◽  
W. R. Bitler
Keyword(s):  
Single Phase ◽  
X Ray Diffraction ◽  
Rich Region ◽  
Average Cell ◽  
X Ray ◽  
Delta Phase ◽  
Cell Dimensions ◽  
Δ Phase ◽  
Morphological Differences ◽  
Concentration Discontinuity

The δ phase is a Zn-rich intermetallic, having a composition range of ∼ 86.5 - 92.0 atomic percent Zn, and is stable up to 665°C. The stoichiometry of the δ phase has been reported as FeZn7 and FeZn10 The deviation in stoichiometry can be attributed to variations in alloy composition used by each investigator. The structure of the δ phase, as determined by powder x-ray diffraction, is hexagonal (P63mc or P63/mmc) with cell dimensions a = 1.28 nm, c = 5.76 nm, and 555±8 atoms per unit cell. Later work suggested that the layer produced by hot-dip galvanizing should be considered as two distinct phases which are characterized by their morphological differences, namely: the iron-rich region with a compact appearance (δk) and the zinc-rich region with a columnar or palisade microstructure (δp). The sub-division of the δ phase was also based on differences in diffusion behavior, and a concentration discontinuity across the δp/δk boundary. However, work utilizing Weisenberg photographs on δ single crystals reported that the variation in lattice parameters with composition was small and hence, structurally, the δk phase and the δp phase were the same and should be thought of as a single phase, δ. Bastin et al. determined the average cell dimensions to be a = 1.28 nm and c = 5.71 nm, and suggested that perhaps some kind of ordering process, which would not be observed by x-ray diffraction, may be responsible for the morphological differences within the δ phase.

Structural and Magnetic Hysteresis Properties of Co-Zr Substituted Hexagonal Barium Ferrites

2015 ◽  
Vol 7 (1) ◽  
pp. 1346-1351
Author(s):  
Ch.Gopal Reddy ◽  
Ch. Venkateshwarlu ◽  
P. Vijaya Bhasker Reddy
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Magnetic Hysteresis ◽  
Grain Morphology ◽  
Hexagonal Structure ◽  
Ion Composition ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
Barium Ferrites ◽  
Xrd Patterns

Co-Zr substituted M-type hexagonal barium ferrites, with chemical formula BaCoxZrxFe12-2xO19 (where x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), have been synthesized by double sintering ceramic method. The crystallographic properties, grain morphology and magnetic properties of these ferrites have been investigated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM). The XRD patterns confirm the single phase with hexagonal structure of prepared ferrites. The magnetic properties have been investigated as a function of Co and Zr ion composition at an applied field in the range of 20 KOe. These studies indicate that the saturation magnetization (Ms) in the samples increases initially up to the Co-Zr composition of x=0.6 and decreases thereafter. On the other hand, the coercivity (Hc) and Remanent magnetization (Mr) are found to decrease continuously with increasing Co-Zr content. This property is most useful in permanent magnetic recording. The observed results are explained on the basis of site occupation of Co and Zr ions in the samples.

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