scholarly journals SH-synthesis of alumino-manganese alloy based on the Al-MnO3 system

2020 ◽  
Vol 16 (2) ◽  
pp. 57-65
Author(s):  
Marina P. Boronenko ◽  
Irina V. Milyukova ◽  
Sergei A. Cheklov
Keyword(s):  
High Hardness ◽  
Hard Alloys ◽  
Structural Components ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
Manganese Alloy ◽  
Preliminary Heating ◽  
X Ray ◽  
High Temperature Synthesis ◽  
Needle Structure

The work is devoted to the use of self-propagating high-temperature synthesis for producing aluminum-manganese alloy in the MnО3 AI system. The experiment was carried out in a specially designed SHS reactor at various pressures with and without preliminary heating. The synthesized samples were studied by X-ray diffraction, metallographic, and X-ray spectral analysis; compression tests were performed. X-ray powder diffraction data showed the presence of intermetallic compounds of different stoichiometries: Al8Mn5, Al11Mn4, and Al6Mn. It was established that the main phase is the Al8Mn5 intermetallic compound. The structure of the sample has a needle structure. The alloy has a high hardness of structural components: from 624 HV to 934 HV. High compressive strength and high hardness are evidence that the synthesized alloy is a direct competitor to hard alloys.

scholarly journals Synthesis of Composite Materials based on TiB2–TiC–Al2O3 and CrB2-Al2O3 in the Combustion Conditions

2021 ◽  
Vol 23 (2) ◽  
pp. 111
Author(s):  
A.J. Seidualiyeva ◽  
K. Kamunur ◽  
R.G. Abdulkarimova ◽  
U. Onuralp ◽  
A.N. Batkal
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
High Hardness ◽  
Unique Combination ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Temperature Oxidation ◽  
X Ray ◽  
High Temperature Synthesis ◽  
Titanium Aluminum

Borides and carbides attract the attention of developers of heat-resistant and super hard structural materials due to a unique combination of their resistance to high-temperature oxidation, high hardness, wear resistance, electrical and thermal conductivity and etc. The article presents experimental results on obtaining composites based on TiB2-TiC-Al2O3, CrB2-Al2O3 by a method combining self-propagating high-temperature synthesis (SHS) and mechanical activation (MA). The influence of the composition of the initial components, the conditions of SHS and preliminary MA on the formation of the microstructure and phase composition of the SHS-composite based on titanium carbide and titanium, chromium borides has been studied. The SHS products were examined by X-ray diffraction analysis and a scanning electron microscope. High-temperature phases of borides of chromium, titanium, aluminum oxide and their spinel are found in SHS products.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Hardening of Selective Laser Melted M2 Steel

2021 ◽  
Author(s):  
Mei Yang ◽  
Yishu Zhang ◽  
Haoxing You ◽  
Richard Smith ◽  
Richard D. Sisson
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
High Hardness ◽  
Steel Part ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Near Net Shape

Abstract Selective laser melting (SLM) is an additive manufacturing technique that can be used to make the near-net-shape metal parts. M2 is a high-speed steel widely used in cutting tools, which is due to its high hardness of this steel. Conventionally, the hardening heat treatment process, including quenching and tempering, is conducted to achieve the high hardness for M2 wrought parts. It was debated if the hardening is needed for additively manufactured M2 parts. In the present work, the M2 steel part is fabricated by SLM. It is found that the hardness of as-fabricated M2 SLM parts is much lower than the hardened M2 wrought parts. The characterization was conducted including X-ray diffraction (XRD), optical microscopy, Scanning Electron Microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) to investigate the microstructure evolution of as-fabricated, quenched, and tempered M2 SLM part. The M2 wrought part was heat-treated simultaneously with the SLM part for comparison. It was found the hardness of M2 SLM part after heat treatment is increased and comparable to the wrought part. Both quenched and tempered M2 SLM and wrought parts have the same microstructure, while the size of the carbides in the wrought part is larger than that in the SLM part.

scholarly journals SHS robust modes to restore molybdenum by combustion wave in MoO3 – Al system

2020 ◽  
Vol 15 (4) ◽  
pp. 27-32
Author(s):  
Irina V. Milyukova ◽  
Marina P. Boronenko
Keyword(s):  
Spectral Analysis ◽  
High Temperature ◽  
Combustion Wave ◽  
Synthesis Process ◽  
Temperature Synthesis ◽  
Preliminary Heating ◽  
X Ray ◽  
Molybdenum Metal ◽  
High Temperature Synthesis ◽  
Oxide Phases

The work is devoted to the technology for the reduction of molybdenum from oxides by the method of self-propagating high-temperature synthesis in the MoO3 AI system with the addition of aluminum. The experiment was carried out in two modes: in a reactor at different pressures without preliminary heating and in a furnace in air until the initiation of the SH-synthesis process. Samples of molybdenum metal were obtained in different synthesis modes. X-ray phase and X-ray spectral analysis showed that molybdenum is the main phase in the synthesized samples. The presence of slag oxide phases Al2O3 and MoO2 was detected.

Microstructure and Hardness of Ni-Cr Porous Preform Reinforced Al-Based Composites by Low Infiltration Method

2011 ◽  
Vol 275 ◽  
pp. 251-254
Author(s):  
Hua Wei Rong ◽  
Cheol Hong Park ◽  
Won Jo Park ◽  
Han Ki Yoon
Keyword(s):  
Intermetallic Compounds ◽  
Rapid Development ◽  
High Hardness ◽  
Optical Microscope ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Infiltration Process ◽  
Pressure Infiltration ◽  
X Ray ◽  
Infiltration Method

With the rapid development of aerospace and automobile industries, metal matrix composites (MMCs) have attracted much attention because of its excellent performance. In this paper, Ni-Cr/AC8A composites reinforced with porous Ni-Cr preform were manufactured by low pressure infiltration process, infiltration temperatures are 700oC~850oC. The microstructure and phase composition of composites were evaluated using optical microscope, X-ray diffraction (XRD) and electro-probe microanalysis (EPMA), It's found that they're intermetallic compounds generated in the composites. Recently, intermetallic compounds have attracted much attention as high-temperature material. We study the hardness of Ni-Cr/AC8A composites, the results show the Ni-Cr/AC8A composite has high hardness due to the intermetallic compounds exist.

Formation of boride layers on a commercially pure Ti surface produced via powder metallurgy

2021 ◽  
Vol 112 (4) ◽  
pp. 303-307
Author(s):  
Yavuz Kaplan ◽  
Mehmet Gülsün ◽  
Sinan Aksöz
Keyword(s):  
Powder Metallurgy ◽  
Substrate Surface ◽  
High Hardness ◽  
Titanium Boride ◽  
Boride Layer ◽  
Powder Metallurgy Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Commercially Pure ◽  
Boriding Process

Abstract In this study, powder metallurgy was applied in a furnace atmosphere to form titanium boride layers on a commercially pure Ti surface. Experiments were carried out using the solid-state boriding method at 900 °C and 1000°C for 12 h and 24 h. Samples were produced by pressing the commercially pure Ti powders under 870 MPa. The sintering process required by the powder metallurgy method was carried out simultaneously with the boriding process. Thus, the sintering and boriding were performed in one stage. The formation of the boride layer was investigated by field emission scanning electron microscopy, optical-light microscopy, X-ray diffraction, and elemental dispersion spectrometry analyses. In addition, microhardness measurements were performed to examine the effect of the boriding process on hardness. The Vickers microhardness of the boronized surface reached 1773 HV, which was much higher than the 150 HV hardness of the commercially pure Ti substrate. The X-ray diffraction analysis showed that the boriding process had enabled the formation of TiB and TiB2 on the powder metallurgy Ti substrate surface. Consequently, the production of Ti via powder metallurgy is a potentially cost-effective alternative to the conventional method, and the boriding process supplies TiB and TiB2 that provide super-high hardness and excellent wear and corrosion resistance.

Microstructure and Mechanical Properties of Fe-Cu-Ni Sinters Prepared by Ball Milling and Hot Pressing

2020 ◽  
Vol 405 ◽  
pp. 379-384
Author(s):  
Joanna Borowiecka-Jamrozek ◽  
Jan Lachowski
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
High Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Composition ◽  
Microstructure And Mechanical Properties ◽  
Static Tensile ◽  
Iron Based ◽  
Surface Observations

The main purpose of this work was to determine the effect of the powder composition on the microstructure and properties of iron-based sinters used as a matrix in diamond tools. The Fe-Cu-Ni sinters obtained from a mixture of ground powders were used for experiments. The influence of manufacturing process parameters on the microstructure and mechanical properties of sinters was investigated. Sintering was performed using hot-pressing technique in a graphite mould. The investigations of obtained sinters included: density, hardness, static tensile test, X-ray diffraction analysis, microstructure and fracture surface observations. The obtained results indicate that the produced sinters have good plasticity and relatively high hardness.

scholarly journals Intermetallic/Ceramic Composites Synthesized from Al–Ni–Ti Combustion with B4C Addition

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 873
Author(s):  
Chun-Liang Yeh ◽  
Chih-Yao Ke
Keyword(s):  
Combustion Velocity ◽  
Ceramic Composites ◽  
The Other ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Reaction Systems ◽  
X Ray ◽  
High Temperature Synthesis ◽  
In Situ Formation

The fabrication of intermetallic/ceramic composites by combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) was investigated in the Al–Ni–Ti system with the addition of B4C. Two reaction systems were employed: one was used to produce the composites of xNiAl–2TiB2–TiC with x = 2–7, and the other was used to synthesize yNi3Al–2TiB2–TiC with y = 2–7. The reaction mechanism of the Al–Ni–Ti system was strongly influenced by the presence of B4C. The reaction of B4C with Ti was highly exothermic, so the reaction temperature and combustion velocity decreased due to increasing levels of Ni and Al in the reactant mixture. The activation energies of Ea = 110.6 and 172.1 kJ/mol were obtained for the fabrication of NiAl- and Ni3Al-based composites, respectively, by the SHS reaction. The XRD (X-ray diffraction) analysis showed an in situ formation of intermetallic (NiAl and Ni3Al) and ceramic phases (TiB2 and TiC) and confirmed no reactions taking place between Ti and Al or Ni. The microstructure of the product revealed large NiAl and Ni3Al grains and small TiB2 and TiC particles. With the addition of TiB2 and TiC, the hardness of NiAl and Ni3Al was considerably increased and the toughness was also improved.

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