Phase equilibrium between bcc solid solution matrix and B2 aluminides in Nb-based alloy

2015 ◽  
Vol 1760 ◽  
Author(s):  
Takuya Yamanouchi ◽  
Seiji Miura
Keyword(s):  
Solid Solution ◽  
Phase Equilibrium ◽  
Phase Field ◽  
Composition Range ◽  
Basic Information ◽  
Two Phase ◽  
Nial Phase ◽  
Solid Solution Matrix ◽  
Solution Matrix

ABSTRACTB2 aluminides have a role of Al reservoir for Al2O3 surface and it is expected to increase oxidation resistance of (Nb,Mo)-bccss substrate. For the accumulation of the basic information to design the alloy composed of B2 coating on bccss matrix, bccss - B2 two-phase field was investigated in the Nb-Mo-Ni-Pd-Al system at 1273 K. It is found that Pd-rich B2-(Ni,Pd)Al phase is in equilibrium with Nb-rich bccss phase, while without Pd, the composition range of bccss coexisting with B2-NiAl phase is limited to be low Nb.

Bcc / B2 phase equilibria and phase transformation from B2 to β’ in refractory Nb-X(Pd, Rh, Ir)-Al

MRS Advances ◽  
2017 ◽  
Vol 2 (25) ◽  
pp. 1335-1340
Author(s):  
T. Yamanouchi ◽  
S. Miura ◽  
M. Ohno ◽  
K. Ikeda
Keyword(s):  
Solid Solution ◽  
Phase Transformation ◽  
Surface Layer ◽  
Phase Field ◽  
Composition Range ◽  
Eutectic Temperature ◽  
Two Phase ◽  
Wide Composition Range ◽  
B2 Phase ◽  
Bcc Phase

ABSTRACTFor the improvement of oxidation resistance of Nb-based alloys, PdAl-B2 is expected as Al reservoir for Al2O3 surface layer because it is in equilibrium with Nbss (bcc) phase. However, PdAl forms cracks during casting caused by B2 -> β’ transformation. To suppress B2 -> β’ transformation, Rh, Ru and Ir were chosen as additive elements. It is found that bcc / B2 two-phase field in Nb-Pd-Ir-Al system is limited to be small fraction of Ir, while (Pd,Rh)Al-B2 is in equilibrium with bcc solid solution in a wide composition range and addition of Rh prevents occurrence of B2 -> β’ transformation. Composition range of (Pd,Ru)Al-B2 in equilibrium with bcc phase is wider than (Pd,Ir)Al-B2 but narrower than (Pd,Rh)Al-B2. Rh and Ru addition are also beneficial for improving eutectic temperature of Nb-bcc / B2 aluminide two-phase alloys.

Phase Equilibrium of Mg-Nd-Zn System near Mg-Nd Side at 400°C

2016 ◽  
Vol 873 ◽  
pp. 18-22
Author(s):  
Ming Li Huang ◽  
Xue Shen ◽  
Hong Xiao Li
Keyword(s):  
Solid Solution ◽  
Phase Equilibrium ◽  
Ternary Isothermal Section ◽  
Phase Region ◽  
X Ray Diffraction ◽  
Maximum Solubility ◽  
Two Phase ◽  
Solubility Range ◽  
Three Phase ◽  
Equilibrium Alloys

The equilibrium alloys closed to Mg-Nd side in the Mg-rich corner of the Mg-Zn-Nd system at 400°C have been investigated by scanning electron microscopy, electron probe microanalysis and X-ray diffraction. The binary solid solutions Mg12Nd and Mg3Nd with the solubility of Zn have been identified. The maximum solubility of Zn in Mg12Nd is 4.8at%, and Mg12Nd phase can be in equilibrium with Mg solid solution. However, only when the solubility range of Zn in 26at%~32.2at%, Mg3Nd can be in two-phase equilibrium with Mg solid solution. As the results, two two-phase regions as Mg+Mg12Nd and Mg+Mg3Nd and a three-phase region as Mg+Mg12Nd+Mg3Nd in Mg-Nd-Zn ternary isothermal section at 400°C have been identified.

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.

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.

Precipitation in Partially-Stabilized Zirconia

1976 ◽  
Vol 34 ◽  
pp. 628-629
Author(s):  
D. L. Porter ◽  
A. H. Heuer
Keyword(s):  
Phase Region ◽  
Precipitate Size ◽  
Tetragonal Symmetry ◽  
Stabilized Zirconia ◽  
Two Phase ◽  
Slow Cooling ◽  
Partially Stabilized Zirconia ◽  
Large Particles ◽  
Solid Solution Matrix ◽  
Solution Matrix

Precipitation in commercial partially-stabilized zirconia (PSZ) has been studied in order to facilitate "alloy design" in these materials. The commercial material used in this study is a 2.8 wt. % MgO alloy and has the cubic flourite structure at its sintering temperature. Upon cooling, a nearly MgO-free ZrO2 phase with tetragonal symmetry precipitates, which on further cooling inverts martensitically to a phase with monoclinic symmetry. At room temperature, commercial PSZ's therefore consist of a cubic solid solution matrix containing monoclinic precipitate; size, morphology, and distribution of the precipitate phase strongly influence mechanical properties.Figures I and II show typical microstructures of the material as it is commercially produced. Both large and small precipitates are present (Figure I), indicative of precipitation over a range of temperatures during slow cooling through the two-phase region. Figure II shows heavily-twinned monoclinic particle; such large particles produced during commercial fabrication are believed to be deleterious to the mechanical behavior.

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.

Grain Refinement of AZ61 Alloy after ECAP Processing

2017 ◽  
Vol 891 ◽  
pp. 372-376 ◽  
Author(s):  
Ondřej Hilšer ◽  
Stanislav Rusz ◽  
Wojciech Maziarz ◽  
Robert Chulist ◽  
Jan Dutkiewicz ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Grain Boundaries ◽  
Two Phase ◽  
Ecap Processing ◽  
The Third ◽  
Az61 Alloy ◽  
Solid Solution Matrix ◽  
Microscopy Techniques ◽  
Electron Back Scattered Diffraction ◽  
Solution Matrix

Electron microscopy techniques were used to characterize the microstructure and deformation behavior of AZ61 alloy proceeded by ECAP. The commercial AZ61 alloy subjected to severe plastic deformation possesses a two-phase microstructure consisting of solid solution matrix and massive γ-phase Mg17Al12, or Mg17(Al,Zn)12 distributed mostly at grain boundaries. Based on selected area diffraction and electron back scattered diffraction applied to a sample after the third pass, it can be concluded that plastic deformation induced by ECAP occurs mainly by slip mode forming a high density network of dislocation inside the grains. The grains size was significantly refined to 1.4 μm after the third pass of ECAP. The refinement of grain size is probably due to polygonization process associated with formation of high angle grain boundaries due to dislocations rearrangement. (Al, Zn)12Mg17 precipitates of size scattered from 100 to 200 nm and also the primary precipitates of Al6Mn phase were observed in this alloy.

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