Sintering process, structure, and phase composition of metal-graphite materials based on nickel alloys

1971 ◽  
Vol 10 (10) ◽  
pp. 786-789
Author(s):  
V. I. Itin ◽  
Yu. I. Kozlov ◽  
L. I. Pugina ◽  
A. G. Yurchenko ◽  
K. V. Savitskii ◽  
...  
Keyword(s):  
Phase Composition ◽  
Nickel Alloys ◽  
Sintering Process ◽  
Process Structure

Sintering process, structure, and phase composition of metal - Graphite materials based on nickel alloys

1971 ◽  
Vol 10 (11) ◽  
pp. 862-866 ◽  
Author(s):  
V. I. Itin ◽  
Yu. I. Kozlov ◽  
A. F. Bykonya ◽  
L. I. Pugina ◽  
A. G. Yurchenko ◽  
...  
Keyword(s):  
Phase Composition ◽  
Nickel Alloys ◽  
Sintering Process ◽  
Process Structure

Investigation of Microstructure and Property of Fe3Al/Al2O3 Composites

2010 ◽  
Vol 150-151 ◽  
pp. 1409-1412 ◽  
Author(s):  
Tao Jiang
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Alloying ◽  
Sintering Process ◽  
Composite Powders ◽  
Al2o3 Composite ◽  
Al2o3 Phase ◽  
The Mean ◽  
Xrd Patterns ◽  
Al2o3 Matrix

The Fe3Al/Al2O3 composites were fabricated by pressureless sintering process. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe3Al powders and Al2O3 powders were mixed and the Fe3Al/Al2O3 composite powders were prepared, so the Fe3Al/Al2O3 composites were fabricated by sintering process at 1700oC for 2h. The phase composition and microstructure of Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical properties of the Fe3Al/Al2O3 composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in the sintered composites. The Fe3Al/Al2O3 composites sintered bulks exhibited the homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix, the mean particles size of Fe3Al intermetallics was about 3-5μm. The Fe3Al/Al2O3 composites exhibited more homogenous and compact microstructure with the increase of Fe3Al content in the Al2O3 matrix. The density and relative density of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The fracture strength and fracture toughness of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The elastic modulus and hardness (HRA) of the Fe3Al/Al2O3 composites decreased gradually with the increase of Fe3Al content.

Effects of High-Energy Ball Milling Time on the Sintering Process of FeSe Superconductors

2016 ◽  
Vol 848 ◽  
pp. 657-663 ◽  
Author(s):  
Sheng Nan Zhang ◽  
Xiao Bo Ma ◽  
Ji Xing Liu ◽  
Jian Qing Feng ◽  
Cheng Shan Li ◽  
...  
Keyword(s):  
Phase Composition ◽  
Ball Milling ◽  
Optimal Parameter ◽  
High Energy ◽  
Superconducting Phase ◽  
High Energy Ball Milling ◽  
Superconducting Transition ◽  
Sintering Process ◽  
Energy Ball ◽  
Precursor Powders

FeSe superconducting bulks were prepared with high energy ball milling (HEBM) aided sintering process, within which process, tetragonal β-FeSe superconducting phase could be formed directly with one step sintering process, and the formation of hexagonal δ-FeSe non-superconducting phase was effectively avoided. The influences of HEBM time on the sintering process of FeSe bulks were systematically investigated. With different HEBM time, the phase composition and morphology of precursor powders changed correspondingly, which thus influenced the final phase composition and superconducting properties of FeSe superconducting bulks. Due to the formation of FeSe bulks with larger tetragonal phase content and higher superconducting transition temperature, HEBM time of 6.0 h was recognized as the optimal parameter. Shorter HEBM time could lead to the insufficient decrease of particle size and low density. While longer HEBM time caused the formation of amorphous hexagonal δ-FeSe, which crystallized during sintering process. Thus no more tetragonal FeSe could be obtained. The FeSe superconducting bulk with the critical temperature Tc(onset) of 8.0 K was obtained with the HEBM time of 6 h, and sintering temperature of 700 oC for 12 h.

scholarly journals Phase composition of galvanic iron-nickel alloys obtained using pulsed current

2021 ◽  
Vol 22 (1) ◽  
pp. 141-145
Author(s):  
R.P. Ganich ◽  
V.O. Zabludovsky ◽  
V.V. Artemchuk ◽  
Y.V. Zelenko ◽  
R.V. Markul
Keyword(s):  
Phase Composition ◽  
Nickel Alloys ◽  
Pulse Current ◽  
Equilibrium Diagram ◽  
Component Composition ◽  
Pulse Action ◽  
Unipolar Pulse ◽  
Iron Nickel ◽  
The Moment ◽  
Iron Nickel Alloys

The paper presents the results of studying the phase composition of iron-nickel alloys obtained by unsteady electrolysis. It was found that the use of a unipolar pulse current leads to a significant increase in the crystallization overvoltage at the crystallization front at the moment of the pulse action, which affects the component composition of the coatings. The phase composition of the alloys formed at the cathode differs from that shown in the iron-nickel equilibrium diagram.

Structure and phase composition of complexly alloyed powdered niobium containing nickel alloys

1988 ◽  
Vol 27 (3) ◽  
pp. 255-259
Author(s):  
L. E. Popova ◽  
V. I. Shvarts ◽  
V. F. Kotov ◽  
R. V. Lapina ◽  
G. B. Zvereva ◽  
...  
Keyword(s):  
Phase Composition ◽  
Nickel Alloys

Effect of NbH Particle Size and Cooling Type on the Microstructure, Phase Composition and Microhardness of Ti-20Nb-20Zr Alloy

2017 ◽  
Vol 899 ◽  
pp. 243-247
Author(s):  
Marcio W.D. Mendes ◽  
Narayanna Marques Ferreira Mendes ◽  
Ana Helena de Almeida Bressiani ◽  
José Carlos Bressiani
Keyword(s):  
Particle Size ◽  
Corrosion Resistance ◽  
Phase Composition ◽  
Titanium Alloys ◽  
Fatigue Resistance ◽  
Toxic Elements ◽  
Vickers Microhardness ◽  
High Strength ◽  
Human Bone ◽  
Sintering Process

Titanium alloys are widely used as implants in orthopedics and dentistry due to their properties such as high strength, corrosion resistance, biocompatibility and good fatigue resistance. Alloys composed of non-toxic elements, like Nb and Zr, provide lowest Young’s modulus with values near to human bone modulus. The goal of this work was to study the effect of NbH particle size and cooling type on the microstructure, phase composition and microhardness of Ti-20Nb-20Zr alloy. The powders were produced by hydrogenation method. Two different powders of NbH were prepared: powders comminuted (C) and comminuted followed by milling (C+M). After, the alloy powders were milling and homogenizated for 6 h / 300 rpm and sintered at 1300 °C / 3h followed furnace cooling. Afterward, the specimens were treated at 1000 °C / 1 h and cooling in air and water. The samples were characterized by XRD, SEM and Vickers microhardness. The results showed that the alloy is classified as α + β. Vickers microhardness of Ti-20Nb-20Zr ranged between 680-700 and 540-600 HV from alloys prepared with NbH-comminuted and NbH comminuted + milled, respectively. Results indicated that NbH agglomerate behave as barriers for the sintering process of the alloy.

Investigation of Microstructure and Property of the Fe3Al/Al2O3 Composites Fabricated by Mechanical Alloying Process and Plasma Active Sintering Process

2011 ◽  
Vol 194-196 ◽  
pp. 1689-1692
Author(s):  
Tao Jiang
Keyword(s):  
Heat Treatment ◽  
Mechanical Property ◽  
Phase Composition ◽  
Mechanical Alloying ◽  
Sintering Process ◽  
Composite Powders ◽  
Al Content ◽  
The Mean ◽  
Xrd Patterns ◽  
Microstructure And Mechanical Property

The Fe3Al/Al2O3composites were fabricated by plasma active sintering process. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe3Al powders and Al2O3powders were mixed and the Fe3Al/Al2O3composite powders were prepared, so the Fe3Al/Al2O3composites were fabricated by plasma active sintering process at 1200°C for 5min under the pressure of 30MPa. The phase composition and microstructure of the Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical property of the Fe3Al/Al2O3composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe3Al phase and Al2O3phase in the sintered composites. The Fe3Al/Al2O3composites sintered bulks exhibited the homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3matrix. The mean particles size of Fe3Al intermetallics was about 2-3μm and mean particles sizes of Al2O3was about 2-3μm. The density and relative density of the Fe3Al/Al2O3composites increased gradually with the increase of Fe3Al content. The fracture strength and fracture toughness of the Fe3Al/Al2O3composites increased gradually with the increase of Fe3Al content. The elastic modulus and hardness(HRA) of Fe3Al/Al2O3composites decreased gradually with the increase of Fe3Al content.

Fabrication and Microstructure of the Fe3Al/Al2O3 Composites by Pressureless Sintering

2010 ◽  
Vol 177 ◽  
pp. 411-414
Author(s):  
Tao Jiang ◽  
Ke Wei Pan
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Alloying ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Al2o3 Phase ◽  
The Mean ◽  
Xrd Patterns ◽  
Al2o3 Matrix

Fe3Al/Al2O3 composites were fabricated by pressureless sintering in this research. Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment. The Fe3Al powders and Al2O3 powders were mixed together, then the Fe3Al/Al2O3 composites were fabricated by pressureless sintering process at 1700oC for 2h. The phase composition and microstructure of the Fe3Al intermetallics compounds powders and the phase composition and microstructure of the sintered Fe3Al/Al2O3 composites were investigated. The XRD patterns results showed that the Fe-Al intermetallics compounds powders were prepared by mechanical alloying for 60h, and the Fe-Al intermetallics compounds powders transformed into Fe3Al intermetallics compounds powders after heat treatment at 800oC and 1000oC. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in the sintered composites. The microstructure showed that the mean particles size of the Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment was rather fine and about 2-3μm. The sintered Fe3Al/Al2O3 composites exhibited homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix. The mean particles size of Fe3Al was about 3-5μm. The sintered Fe3Al/Al2O3 composites exhibited more homogenous and compact microstructure with the increase of Fe3Al content in the Al2O3 matrix.

Increasing the heat resistance of cast nickel-based complex alloyed alloys due to the influence of the redistribution of alloying elements between the γ-solid solution and the strengthening intermetallic γ'-phase

2020 ◽  
pp. 67-79
Author(s):  
O.M. Gubanov ◽  
V.N. Gadalov ◽  
Yu.V. Skripkina ◽  
I.A. Makarova
Keyword(s):  
Phase Composition ◽  
Heat Resistance ◽  
Nickel Alloys ◽  
Diffusion Processes ◽  
Distribution Coefficients ◽  
Alloying Elements ◽  
Maximum Heat ◽  
Alloying System ◽  
Heat Resistant ◽  
Positive Effect

The analysis of alloying of the chemical and phase composition of domestic and foreign cast heat-resistant alloys with a nickel matrix is carried out; the tendency to increase the level of heat-resistant properties of cast nickel alloys due to more complex alloying is traced. Recently, expensive rhenium, ruthenium, hafnium, and dysprosium have increasingly been used as alloying elements. The positive effect of these elements on the thermal stability of the γ-matrix and the strengthening γ'-phase is established. The above elements inhibit diffusion processes, thereby increasing the creep resistance of alloys at high temperatures and loads. The evaluation of heatresistant nickel alloys obtained by directional crystallization is given. It is established that the most significant parameters of the phase composition of the studied alloys are the distribution coefficients of alloying elements between the γ' and γ-phases (Ki). The basic principles of balanced alloying, which are used to select the optimal chemical composition of heat-resistant nickel alloys, are formulated. To achieve the maximum heat resistance parameters in the selected heat-resistant nickel alloys alloying system, the calculated value γ/γ' defined by “misfit” was used, which is calculated by the formula: Δа = (аγ-аγ')/ аγ, where аγ and аγ' are the lattice periods of γ and γʹ-phases. Thus, the calculated Δа should be positive for аγ> аγ' and at least two to three times more than for single-crystal heat-resistant nickel alloys with a traditional alloying system, for which Δа = (0.1-0.2) or more. It is shown that misfit (γ/γ') is mainly determined by those alloying elements that increase the аγ most significantly. These elements are Re, Pu, Mo, W, Nb, and Ta in ascending order of influence on the lattice period (аγ) of the phase.

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