scholarly journals Structure, physical and mechanical properties of bronze castings obtained by continuous and centrifugal casting

2020 ◽  
pp. 26-28
Author(s):  
E. I. Marukovich ◽  
V. A. Kharkov ◽  
I. O. Sazonenko ◽  
V. A. Kukareko ◽  
A. V. Kushnerov
Keyword(s):  
Continuous Casting ◽  
Centrifugal Casting ◽  
Physical And Mechanical Properties ◽  
Lattice Parameter ◽  
Matrix Phase ◽  
Solid Solution Hardening ◽  
Crystal Lattice Parameter ◽  
X Ray Diffraction ◽  
The Matrix ◽  
Crystallization Conditions

The influence of crystallization conditions (continuous and centrifugal casting) of small-sized BrА1Fe4Ni4 bronze castings on the structure, phase composition, and hardness was studied. It was found by metallographic and X-ray diffraction methods that the castings consist of (α + γ')-eutectoid, α phase and AlCu, Al2Cu3 intermetallic compounds. The matrix phase in the alloy, crystallized by centrifugal casting, due to its higher alloying with Al atoms, has an increased value of the crystal lattice parameter, compared with the case of continuous casting. The hardness of the casting obtained by centrifugal casting increases compared with continuous casting, which is due to the formation of a more dispersed structure, as well as a large solid solution hardening of the matrix phase of the casting.

High Temperature Mechanical Properties of Ni-Al-Cr Based Alloys with Refractory Alloying Elements

2006 ◽  
Vol 510-511 ◽  
pp. 358-361
Author(s):  
Won Yong Kim ◽  
Han Sol Kim ◽  
In Dong Yeo ◽  
Mok Soon Kim
Keyword(s):  
High Temperature ◽  
Volume Fraction ◽  
Lattice Parameter ◽  
Alloying Elements ◽  
Solid Solution Hardening ◽  
High Temperature Strength ◽  
High Temperature Mechanical Properties ◽  
Die Materials ◽  
The Matrix ◽  
Effective Role

We report on advanced Ni3Al based high temperature structural alloys with refractory alloying elements such as Zr and Mo to be apllied in the fields of die-casting and high temperature press forming as die materials. The duplex microstructure consisting of L12 structured Ni3Al phase and Ni5Zr intermetallic dispersoids was observed to display the microstructural feature for the present alloys investigated. Depending on alloying elements, the volume fraction of 2nd phase was measured to be different, indicating a difference in solid solubility of alloying elements in the matrix γ’ phase. Lattice parameter of matrix phase increased with increasing content of alloying elements. In the higher temperature region more than 973K, the present alloys appeared to show their higher strength compared to those obtained in conventional superalloys. On the basis of experimental results obtained, it is suggested that refractory alloying elements have an effective role to improve the high temperature strength in terms of enhanced thermal stability and solid solution hardening.

scholarly journals Effect of Basicity on the Sulfur Precipitation and Occurrence State in Kambara Reactor Desulfurization Slag

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 977
Author(s):  
Renlin Zhu ◽  
Jianli Li ◽  
Jiajun Jiang ◽  
Yue Yu ◽  
Hangyu Zhu
Keyword(s):  
Grain Boundary ◽  
Molten Slag ◽  
Slag Sample ◽  
Solidification Process ◽  
Matrix Phase ◽  
X Ray Diffraction ◽  
Initial Stage ◽  
The Matrix ◽  
Amorphous Sulfur ◽  
Occurrence State

Kambara Reactor (KR) desulfurization slag used as slag-making material for converter smelting can promote early slag melting in the initial stage and improve the efficiency of dephosphorization. However, its direct utilization as a slagging material can increase the sulfur content in molten steel since KR desulfurization slag contains 1~2.5% sulfur. Therefore, this research focuses on the effect of basicity on the precipitation behavior and occurrence state of sulfur in KR desulfurization slag in order to provide an academic reference for the subsequent removal of sulfur from slag through an oxidizing atmosphere. The solidification process of slag was simulated by the Factsage8.0. The slag samples were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM), and the amount of CaS grains was analyzed using Image-ProPlus6.0 software. The thermodynamic calculation showed that the crystallization temperature of CaS in the molten slag gradually decreased with the increase in basicity, and the CaS crystals in the molten slag mainly existed in the matrix phase and at the silicate grain boundaries. A large number of CaS grains were precipitated along the silicate grain boundary in low-basicity (R = 2.5 and 3.0) slags and fewer CaS grains were precipitated along the silicate grain boundary, while the CaS grain density in the matrix phase was higher in the high-basicity (R = 3.5, 4.0, 4.5) slag. With the increase in basicity, the number of CaS grains gradually decreased, and the CaS grain sizes in slag sample increased gradually. The sulfur in the synthetic slag was in the form of CaS crystals and the amorphous phase, and the content of amorphous sulfur gradually increased with increasing basicity.

Effect of TiC Particles Volume Fraction on the Mutual Diffusion of Al and Mg during Fabrication of Al-4.5wt%Mg/TiC via Mechanical Alloying Process

2012 ◽  
Vol 326-328 ◽  
pp. 141-146 ◽  
Author(s):  
O. Ozhdelnia ◽  
Ali Shokuhfar
Keyword(s):  
Mechanical Alloying ◽  
Volume Fraction ◽  
Weight Ratio ◽  
Lattice Parameter ◽  
Mutual Diffusion ◽  
X Ray Diffraction ◽  
The Matrix ◽  
Elemental Diffusion ◽  
Diffraction Patterns ◽  
Composite Samples

In this work the effects of volume fraction at different milling times and impact forces, defined as the ball-to-powder weight ratio (BPR), on the elemental diffusion during mechanical alloying process of Al-4.5wt%Mg/TiC composite were evaluated and compared with the TiC free samples (Al-4.5wt%Mg alloy). X-ray diffraction patterns of the monolithic and composite samples imply the fact that a higher level of mutual diffusion of constituents, Al and Mg, happened in the matrix in the presence of TiC particles. This effect of the reinforcing particles can be attributed to the increased densities of dislocation and vacancy caused by the presence of TiC particles within the matrix-giving rise to increasing the micro-strain, lattice parameter and decreasing the crystallite size. Scanning electron microscopy (SEM) was used not only to study the morphology of the powders but also to show the fact that the TiC powders were distributed during MA process. The TEM and HRTEM results showed that powder produced in this work has a nanosize.

Fully Automated High-Precision X-Ray Diffraction

1967 ◽  
Vol 11 ◽  
pp. 359-375 ◽  
Author(s):  
T. W. Baker ◽  
J. D. George ◽  
B. A. Bellamy ◽  
R. Causer
Keyword(s):  
Automatic Control ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Performance Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Data Processor ◽  
On Line ◽  
Absolute Measurements ◽  
Monitor Program

AbstractX-ray diffraction angles are measured precisely, conveniently, and automatically by a specially designed instrument, the automatic precision X-ray goniometer connected on line to an Elliott 903B data processor. A monitor program controls two such instruments and two diffractometers simultaneously and allows a comprehensive set of experiments to be performed. The sensitivity is such that, when translated into terms of changes in the crystal-lattice parameter, a precision of 1 part in 10,000,000 is being attained, and indications are that absolute measurements are almost as good. The procedures, instrument, and automatic control are described, and the results of performance tests and some applications are given.

The Ageing of Beryllium Bronze in the Pulse Magnetic Field

2008 ◽  
Vol 277 ◽  
pp. 81-85
Author(s):  
J.V. Osinskaya ◽  
A.V. Pokoev
Keyword(s):  
Magnetic Field ◽  
Pulse Magnetic Field ◽  
Physical And Mechanical Properties ◽  
Coherent Scattering ◽  
Lattice Parameter ◽  
Beryllium Bronze ◽  
Residual Matrix ◽  
Matrix Blocks ◽  
The Matrix ◽  
Dislocations Density

Kinetics of changes of microstructure of beryllium bronze BrB-2 in d decomposition process of supersaturated solid solution in the pulse magnetic field with 0 – 7 Hz frequency with pulse intensity amplitude 318.4 кA/m (4 kOe) and magnetic field constant component 238.8 кA/m (3 kOe) under the temperature 350 °С and ageing duration 1 hour was investigated by microhardness measurements and X-ray diffraction. Frequency dependences of microhardness, lattice parameter, beryllium concentration in a residual matrix, size of coherent scattering blocks, dislocations density and the value of relative microdeformation of the matrix blocks under ageing in the pulse magnetic field and without it have been investigated. Experiment results show that the pulse magnetic field essentially influences the parameters of the fine structure and also physical and mechanical properties of bronze.

scholarly journals Lattice Misfit of High Refractory Ruthenium Containing Nickel-Base Superalloys

2011 ◽  
Vol 278 ◽  
pp. 60-65 ◽  
Author(s):  
Steffen Neumeier ◽  
J. Ang ◽  
R.A. Hobbs ◽  
Catherine M.F. Rae ◽  
Howard J. Stone
Keyword(s):  
Lattice Misfit ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Matrix ◽  
Coherency Stress ◽  
Matrix Lattice ◽  
Chemical Segregation ◽  
Nickel Base Superalloys ◽  
Nickel Base

The influence of Ru, Co, Mo and W on the lattice misfit of eight highly alloyed Re containing single crystal nickel-base superalloys was investigated. High resolution X-ray diffraction (XRD) was used to relate the elemental partitioning behavior and the Vegard coefficients of the elements under investigation to the measured lattice parameter of the  and  phase. The residual chemical segregation and especially the coherency stress-induced tetragonal distortion of the  matrix lattice in the high Mo containing alloys results in the observation of two different lattice parameters for the  matrix phase. This leads to three overlapping, but clearly distinguishable {002} X-ray reflections.

scholarly journals Effect of Surface Modification of a Titanium Alloy by Copper Ions on the Structure and Properties of the Substrate-Coating Composition

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1591
Author(s):  
Marina Fedorischeva ◽  
Mark Kalashnikov ◽  
Irina Bozhko ◽  
Olga Perevalova ◽  
Victor Sergeev
Keyword(s):  
Titanium Alloy ◽  
Copper Ions ◽  
Nanocrystalline Structure ◽  
Ceramic Coatings ◽  
Lattice Parameter ◽  
Strength Properties ◽  
Crystal Lattice Parameter ◽  
X Ray Diffraction ◽  
Processing Times ◽  
Cyclic Resistance

To improve the strength properties, adhesion, and the thermal cycling resistance of ceramic coatings, the titanium alloy surface was modified with copper ions under different processing times. It is found that at the maximum processing time, the thickness of the alloyed layer reaches 12 μm. It is shown that the modified layer has a multiphase structure in addition to the main α and β–titanium phases with the intermetallic compounds of the Ti-Cu system. The parameters of the fine structure of the material are investigated by the X-ray diffraction analysis. It has been found that when the surface of the titanium alloy is modified, depletion occurs in the main alloying elements, such as aluminum and vanadium, the crystal lattice parameter increases, the root-mean-square (rms) displacements of the atoms decrease, and the macrostresses of compression arise. A multilevel micro- and nanoporous nanocrystalline structure occurs, which leads to an increase in the adhesion and the thermal cyclic resistance of the ceramic coating based on Si-Al-N.

scholarly journals Characterization of γ′ Precipitates in Cast Ni-Based Superalloy and Their Behaviour at High-Homologous Temperatures Studied by TEM and in Situ XRD

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2397 ◽  
Author(s):  
Łukasz Rakoczy ◽  
Ondrej Milkovič ◽  
Bogdan Rutkowski ◽  
Rafał Cygan ◽  
Małgorzata Grudzień-Rakoczy ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Matrix Material ◽  
High Volume ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
In Situ Xrd ◽  
Transmission Electron ◽  
The Matrix

In situ X-ray diffraction and transmission electron microscopy has been used to investigate René 108 Ni-based superalloy after short-term annealing at high-homologous temperatures. Current work is focused on characterisation of γ′ precipitates, their volume fraction, evolution of the lattice parameter of γ and γ′ phases and misfit parameter of γ′ in the matrix. Material in the initial condition is characterised by a high-volume fraction (over 63%) of γ′ precipitates. Irregular distribution of alloying elements was observed. Matrix channels were strongly enriched in Cr, Co, W and Mo, whereas precipitates contain large amount of Al, Ti, Ta and Hf. Exposure to high-homologous temperatures in the range 1100–1250 °C led to the dissolution of the precipitates, which influenced the change of lattice parameter of both γ and γ′ phases. The lattice parameter of the matrix continuously grew during holding at high temperatures, which had a dominant influence on the more negative misfit coefficient.

Effect of Trace Element Er on Al-Mg and Al-Mg-Mn Alloys

2007 ◽  
Vol 546-549 ◽  
pp. 899-904 ◽  
Author(s):  
Ze Bing Xing ◽  
Zuo Ren Nie ◽  
Jing Xia Zou ◽  
Xiao Lan Ji ◽  
Xu Dong Wang
Keyword(s):  
Trace Element ◽  
Lattice Parameter ◽  
Heating Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Matrix ◽  
Heterogeneous Nucleus ◽  
Coherent Relationship ◽  
Scanning Electron

The behaviors of trace element Er on binary Al-Mg and ternary Al-Mg-Mn alloys have been investigated through optical microscopy, x-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy and transmission electron microscope. It was found that Er additions more than 0.4% (wt%) produced a remarkable refinement in grain size of Al-Mg and Al-Mg-Mn alloys castings. Er can enhance the tensile strength of the two group experimental alloys significantly but not greatly decrease the elongation due to the formation of many fine like spherical and dispersive primary and precipitation Al3Er particles during casting and heating process. Al3Er particles have L12 crystal structure (space group Pm3m) with a lattice parameter of 0.42119nm, and have a coherent relationship with the matrix phase α-Al (mismatch only 4.1%), which can be acted as the heterogeneous nucleus during solidification to increase the rate of nucleation, and the other hands it can strongly pin up dislocations and subgrain boundaries and retard the recrystallization of alloys.

Hydride structures in Ti-aluminides subjected to high temperature and hydrogen pressure charging conditions

1991 ◽  
Vol 6 (6) ◽  
pp. 1230-1237 ◽  
Author(s):  
D. Legzdina ◽  
I.M. Robertson ◽  
H.K. Birnbaum
Keyword(s):  
Single Phase ◽  
Vacuum Annealing ◽  
Lattice Parameter ◽  
Matrix Composition ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
The Matrix ◽  
Diffraction Patterns ◽  
Fcc Structure

The distribution and chemistry of hydrides produced in single and dual phase alloys with a composition near TiAl have been investigated by using a combination of TEM and x-ray diffraction techniques. The alloys were exposed at 650 °C to 13.8 MPa of gaseous H2 for 100 h. In the single-phase gamma alloy, large hydrides preferentially nucleated on the grain boundaries and matrix dislocations and a population of small hydrides was distributed throughout the matrix. X-ray and electron diffraction patterns from these hydrides indicated that they have an fcc structure with a lattice parameter of 0.45 nm. EDAX analysis of the hydrides showed that they were enriched in Ti. The hydrides were mostly removed by vacuum annealing at 800 °C for 24 h. On dissolution of the hydrides, the chemistry of hydride-free regions of the grain boundary returned to the matrix composition, suggesting that Ti segregation accompanied the hydride formation rather than Ti enrichment causing the formation of the hydride. The hydrogen content in the two-phase (γ-α2) alloy was approximately three times that of the single phase alloy, which was presumably a consequence of the presence of the α2-Ti3Al phase in the two-phase alloy. The hydrides in the two-phase material were shown by x-ray diffraction to have an fcc structure and were removed on annealing in vacuum at 800 °C for 24 h.

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