Characteristics of Ni- Cr Binary Alloys Produced by Conventional Powder Metallurgy

2020 ◽  
Vol 835 ◽  
pp. 214-222
Author(s):  
Lamiaa Z. Mohamed ◽  
Omayma A. El Kady ◽  
Mohamed. M. Lotfy ◽  
Hafiz A. Ahmed ◽  
Fawzi A. Elrefaie
Keyword(s):  
Solid Solution ◽  
Powder Metallurgy ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Cr Content ◽  
Matrix Microstructure ◽  
The Matrix ◽  
Solid Solution Matrix ◽  
Equiaxed Grains ◽  
Solution Matrix

The characteristics of Ni-Cr porous alloys containing 0.5 wt%Cr up to 12 wt%Cr were determined. The alloys were prepared from a mix of Ni-particles with filamentary shape and Cr-particles with irregular shape which then mixed with 0.5 wt% paraffin wax as a binder. The samples were formed by compaction and then sintered at 1200 °C for 1 h. The microstructure of samples was found to consist of a Ni-Cr solid solution matrix with X-ray energy dispersive analysis of Cr% less than 0.33 wt%. The matrix microstructure which composed of equiaxed grains (20-60 μm) surrounded high Cr content islands which also contained γ phase (Ni2.88 Cr1.22). The apparent density of the alloys was found to decrease with Cr content from 8.32 g/cm3 for samples containing 0.5 wt%Cr to 7.26 g/cm3 for samples containing 12 wt%Cr. Therefore, the estimated porosity was found to increase from 6.4% to 16.6% with increasing Cr content from 0.5 wt% to 12 wt%. The microhardness of the samples varied from 153.6 to 284.2 VHN for the equiaxed grains and from 119.6 to 240.6 VHN for the island areas.

scholarly journals Microstructure of Oxide Dispersion Strengthened Steel With Cr Content Variation

2020 ◽  
Vol 21 (1) ◽  
pp. 35
Author(s):  
Marzuki Silalahi ◽  
Bernadus Bandriyana ◽  
Arbi Dimyati ◽  
Bambang Sugeng ◽  
Syahfandi Ahda ◽  
...  
Keyword(s):  
High Temperature ◽  
Phase Distribution ◽  
Oxide Dispersion Strengthened ◽  
High Energy ◽  
Oxide Dispersion ◽  
X Ray ◽  
Hardness Tester ◽  
Cr Content ◽  
Ods Steel ◽  
The Matrix

Microstructure and phase distribution of innovative Oxide Dispersion Strengthened (ODS) steel based on Fe-Cr-ZrO2 particularly for application at high temperature reactor with variation of Cr content was analysed. The alloy was synthesized with Cr composition variation of  15, 20 and 25 wt.% Cr, while zirconia dispersoid kept constant at 0.50 wt.%. The samples was synthesized by mechanical alloying comprising of high energy milling for 3 hours followed by vibrated compression with iso-static load at 20 ton. The final consolidation was performed via sintering process for 4 minutes using the Arc Plasma Sintering (APS) technique, a new method developed in BATAN especially for synthesizing high temperature materials. The samples were then characterized by means of scanning electron microscopy (SEM) with energy dispersed X-ray (EDX) analysis capability and X-ray diffraction. The mechanical property of hardness was measured using standard Vickers micro hardness tester to confirmed the microstructure analysis.  The results show that the microstructure of the ODS alloy samples in all variation of Cr content consists generally of cubic Fe-Cr matrix phase with small of porosity and  Zirconia particles distributed homogenously in and around the matrix grains. The achievable hardness was between 142 and 184 HVN dependent consistently on Cr content in which Cr element may cause grain refining that in turn increase the hardness.

scholarly journals EBSD Analysis of Metal Matrix Nanocomposite Microstructure Produced by Powder Metallurgy

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 878 ◽  
Author(s):  
Íris Carneiro ◽  
Filomena Viana ◽  
Manuel F. Vieira ◽  
José V. Fernandes ◽  
Sónia Simões
Keyword(s):  
Powder Metallurgy ◽  
Advanced Materials ◽  
Sintering Process ◽  
Electron Backscattered Diffraction ◽  
Matrix Microstructure ◽  
Metal Matrix Nanocomposite ◽  
The Matrix ◽  
Dislocation Annihilation ◽  
Metal Nanocomposites ◽  
Matrix Nanocomposite

The development of metal nanocomposites reinforced by carbon nanotubes (CNTs) remains a focus of the scientific community due to the growing need to produce lightweight advanced materials with unique mechanical properties. However, for the successful production of these nanocomposites, there is a need to consolidate knowledge about how reinforcement influences the matrix microstructure and which are the strengthening mechanisms promoting the best properties. In this context, this investigation focuses on the study of the reinforcement effect on the microstructure of an Ni-CNT nanocomposites produced by powder metallurgy. The microstructural evolution was analysed by electron backscattered diffraction (EBSD). The EBSD results revealed that the dispersion/mixing and pressing processes induce plastic deformation in the as-received powders. The dislocation structures produced in those initial steps are partially eliminated in the sintering process due to the activation of recovery and recrystallization mechanisms. However, the presence of CNTs in the matrix has a significant effect on the dislocation annihilation, thus reducing the recovery of the dislocation structures.

Microstructures and Mechanical Properties of Consolidated Mg-Zn-Y Alloy

2007 ◽  
Vol 534-536 ◽  
pp. 833-836 ◽  
Author(s):  
J.K. Lee ◽  
Taek Soo Kim ◽  
Ha Guk Jeong ◽  
Jung Chan Bae
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Spark Plasma Sintering ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Solid Solution Matrix ◽  
Solution Matrix ◽  
Consolidation Temperature

The microstructure and mechanical properties of the Mg97Zn1Y2 alloy prepared by spark plasma sintering of gas atomized powders have been investigated. After consolidation, precipitates were observed to form in the α-Mg solid solution matrix of the Mg97Zn1Y2 alloy. These precipitates consisted of Mg12YZn and Mg24Y5 phases. The density of the consolidated bulk Mg-Zn-Y alloy was 1.86 g/cm3. The ultimate tensile strength and elongation were dependent on the consolidation temperature, which were in the ranges of 280 to 293 MPa and 8.5 to 20.8 %, respectively.

Synthesis, Microstructure, and Mechanical Properties of FeCo-VC Composites

2006 ◽  
Vol 980 ◽  
Author(s):  
Hongbin Bei ◽  
E. P. George
Keyword(s):  
Mechanical Properties ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Eutectic Structure ◽  
Directionally Solidified ◽  
Quaternary Alloys ◽  
The Matrix ◽  
Solid Solution Matrix ◽  
Solution Matrix

AbstractFe-Co-V-C quaternary alloys were drop cast and directionally solidified to obtain an in situ composite. It is found that the fully eutectic structure occurs at a composition of Fe - 40.5Co -10.4V- 8.6C (at. %) in a drop-cast alloy. Directional solidification of this composition in a high-temperature optical floating zone furnace produces a well-aligned microstructure, consisting of sub-micron VC fibers (~19% by volume) embedded in a FeCo-5V solid solution matrix containing ~ 1% C. The temperature dependencies of mechanical properties of this composite were examined by tensile tests and the composite was found to have higher yield strength and lower ductility than the matrix.

Nucleation and growth of iron oxides in olivines, (Mg,Fe)2SiO4

1970 ◽  
Vol 37 (291) ◽  
pp. 790-800 ◽  
Author(s):  
P. E. Champness
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Amorphous Silica ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
X Ray ◽  
The Matrix ◽  
Equiaxed Grains

SummaryIron-rich olivines have been oxidized in air in the laboratory and the mechanism of their breakdown has been elucidated using X-ray diffraction and electron microscopy. Low-temperature oxidation (500–800 °C) produces well-oriented hematite- and magnetite-like precipitates together with amorphous silica. The reaction is a cellular one in which thin needles of oxide about 50–100 Å apart grow into the matrix separated by regions of amorphous silica. Nucleation of spherical colonies of the iron oxide and silica occurs on dislocations.Although the hematite or magnetite always shows the same topotactic relationship with the matrix, the direction in which the needle-like precipitates grow is determined by the orientation of the nucleating dislocation. The small size and highly distorted nature of these precipitates accounts for the diffuseness of their X-ray reflections.Oxidation at 1000 °C produces undistorted equiaxed grains of the oxides about 0·2 μm in size. They are surrounded by silica, which produces a disordered electron diffraction pattern. As the temperature is raised, the silica achieves more structural order and the oxide grains increase in size.

scholarly journals Microstructural Characteristics in Babbitt Coatings Deposited by LPCS

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 689
Author(s):  
Wolfgang Tillmann ◽  
Leif Hagen ◽  
Mohamed Abdulgader ◽  
Mark Dennis Kensy ◽  
Michael Paulus
Keyword(s):  
Solid Solution ◽  
Substrate Temperature ◽  
Thermal Spraying ◽  
Cold Spraying ◽  
Maximum Load ◽  
Gas Temperature ◽  
Microstructural Characteristics ◽  
Mesoscopic Structure ◽  
Solid Solution Matrix ◽  
Solution Matrix

Studies have already established that the mechanical properties of Babbitt coatings significantly depend on the microstructural characteristics, such as the amount and distribution of intermetallic compounds dispersed in a soft solid solution matrix. For Sn–Sb–Cu-based Babbitt coatings, the formation of SbSn- and CuSn-based precipitates has a substantial influence on the resulting microhardness and thus determines the maximum load carrying capacity. Thermal spraying of Sn-based Babbitt coatings results in a relatively more refined structure of these precipitates than in common manufacturing processes, such as casting, due to the thermal processing conditions. This study aims to evaluate the effect of the temperature of the propellant gas and substrate temperature on the microstructural characteristics of Sn–Sb–Cu-based Babbitt coatings deposited by low pressure cold spraying (LPCS). The deposits were examined for their phase composition, microhardness and mesoscopic structure. It was found that the coatings were mainly composed of Sb2Sn23, Sb0.49Sn0.51 and Sorosite (CuSn or CuSb0.115Sn0.835), regardless of the substrate temperature or temperature of the propellant gas to be investigated. For a gas temperature above 300 °C, an increased microhardness was observed, which correlates with the appearance of a more homogenous distribution of Sb0.49Sn0.51 dispersed in a soft Sn-rich solid solution matrix.

Microstructure and Strengthening Mechanism of Natural Aging of TZS88 Aluminum Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 59-64
Author(s):  
Chong Cai Zhang ◽  
Yong Fei Yang ◽  
Wei Xing Wu ◽  
Long Wang
Keyword(s):  
Solid Solution ◽  
Aluminum Alloy ◽  
Natural Aging ◽  
Strengthening Mechanism ◽  
Dispersion Strengthening ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Solid Solution Matrix ◽  
Solution Matrix ◽  
Scanning Electron

In this paper, TZS88 aluminum alloy mechanical properties of three months of natural aging is tested, the microstructure and the strengthening mechanism is studied by the application of optical metallographic microscope and scanning electron microscopy. The results show that TZS88 aluminum reinforced mainly caused by solid solution strengthening, aging strengthening and dispersion strengthening, and as such its tensile strength, hardness and elongation in the natural aging have reached ZQSn6-6-3 bronze level, the microstructure are compounds which included α(Al) solid solution matrix + Sn + s, θ, T, ε etc.

Microstructure Evolution of In Situ Synthesized VC Reinforced Iron Matrix Composites

2012 ◽  
Vol 217-219 ◽  
pp. 71-74
Author(s):  
Jing Wang ◽  
Si Jing Fu ◽  
Shu Yong Jiang ◽  
Hong Cheng
Keyword(s):  
Electron Microscopy ◽  
In Situ Synthesis ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Iron Matrix ◽  
X Ray ◽  
Matrix Microstructure ◽  
The Matrix ◽  
Scanning Electron

Iron matrix composite reinforced with VC reinforcements was produced by in situ synthesis technique. The microstructure of the composites was characterized by X-ray diffraction and scanning electron microscopy. The micrographs revealed the morphology and distribution of the reinforcements. The results show that the composite consists of VC carbide as the reinforcing phase and α-Fe as the matrix. The distribution of spherical VC particulates in iron matrix is uniform, and the matrix microstructure of Fe-VC composite is pearlite.

Ni-Based Alloy Coating on Plain-Carbon Steel by Hot Dipping Process

2011 ◽  
Vol 361-363 ◽  
pp. 609-614
Author(s):  
Tao Lin ◽  
Li Sheng Wang ◽  
Zhi Shan Gao ◽  
Zhi Meng Guo
Keyword(s):  
Solid Solution ◽  
Steel Substrate ◽  
Alloy Coating ◽  
Plain Carbon Steel ◽  
Columnar Dendrite ◽  
Light Band ◽  
Coating Microstructure ◽  
Dipping Process ◽  
Solid Solution Matrix ◽  
Solution Matrix

A layer of Ni-Cr-Si-B-Fe alloy was successfully coated on plain steel substrate by hot dipping process. The Ni-Cr-Si-B-Fe alloy coating has a homogeneous thickness of 3mm. The chemical composition and microstructure were studied with SEM and XRD in this paper. The result shows that the Ni-Cr-Si-B-Fe alloy coating is defect-free and chemical bonded with plain steel substrate. A light band zone of 8-10 m width is between Ni-Cr-Si-B-Fe alloy coating and plain steel substrate, and may be considered as a quickly solidified layer. The coating microstructure is a heterogeneous microstructure and changes from the light band zone to the surface of the coating, which is composed mainly of coarse columnar dendrite, needle-like precipitates and scattered eutectic structures. Four regions across the thickness of Ni brazing alloy coating, due to solidification conditions upon hot-dipping, have been identified with distinguished microstructure. In γ-(Fe, Ni) solid solution matrix, the hard phases of CrB, Fe2B and Cr23C6 is identified in the coating.

The Microstructural Peculiarities of Beryllium Bronze after Heat Treatment

2020 ◽  
Vol 989 ◽  
pp. 172-176
Author(s):  
V.R. Baraz ◽  
S.X. Estemirova ◽  
E.A. Ishina
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Supersaturated Solid Solution ◽  
Strength Properties ◽  
Micro Hardness ◽  
Beryllium Bronze ◽  
Phase Type ◽  
Solid Solution Matrix ◽  
Χ Phase ◽  
Solution Matrix

In this article, the microstructural peculiarities and properties of dispersion-hardened beryllium bronze with Ni and Ti are studied after quenching (780 °C) in a supersaturated solid solution and aging (320 °C, 3h). Decomposition of the α-solid solution matrix is implemented by means of an intermittent reaction with a primary allocation intermetallic χ-phase (type Be12Ti) with a VCT-lattice. It is shown that the strength properties (yield strength, micro-hardness) of the alloy more than double after aging.

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