Grain Size and Strength of the Ni3Al Intermetallic Compound Synthesized under Pressure

2021 ◽  
Vol 313 ◽  
pp. 41-49
Author(s):  
Vladimir Ovcharenko ◽  
Alexander Kozulin ◽  
K.O. Akimov
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Intermetallic Compound ◽  
Stoichiometric Composition ◽  
Strength Properties ◽  
Grain Structure ◽  
Significant Shift ◽  
Anomalous Temperature ◽  
High Temperature Synthesis ◽  
Transmission Electron

This paper presents the results of the investigation of the grain structure formation in the intermetallic compound Ni3Al under conditions of its high-temperature synthesis under pressure in a powder mixture of nickel and aluminum of stoichiometric composition and the effect of grain size on the strength properties of the synthesized intermetallic compound. The grain structure was investigated by optical metallography, transmission electron microscopy, and EBSD analysis; the ultimate tensile strength of the intermetallic compound was investigated under the tension of the samples in the temperature range from 20 to 1000 °C. It was found that with a decrease in the grain size, not only does the tensile strength of the intermetallic compound multiply increases but also on the anomalous temperature dependence of the intermetallic compound strength there is a significant shift in the maximum strength value to the region of higher temperatures.

Features of Regularities of Ni3Al Intermetallic Compound High-Temperature Synthesis in a Powder Mixture (3Ni + Al) under Pressure

2018 ◽  
Vol 938 ◽  
pp. 41-45
Author(s):  
K.O. Akimov ◽  
E.N. Boyangin ◽  
Vladimir E. Ovcharenko
Keyword(s):  
High Temperature ◽  
Intermetallic Compound ◽  
Powder Mixture ◽  
Exothermic Reaction ◽  
Strength Properties ◽  
Grain Structure ◽  
Temperature Synthesis ◽  
Compound Formation ◽  
High Temperature Synthesis ◽  
Intermetallic Compound Formation

The results of investigation of the time and power parameters influence of high-temperature synthesis under pressure on the grain structure formation and strength properties of the Ni3Al intermetallic compound are presented and discussed. Dependences of the grain size in the intermetallic compound synthesized under pressure and its strength properties on the value of the preload on the initial powder mixture (3Ni + Al) and on the delay time of pressure application to the thermoreacting system were determined from the time of initiation of intermetallic compound formation volumetric exothermic reaction.

Fabrication of a New Al-Ti-C Master Alloy and its Refining Effect on AZ31

2015 ◽  
Vol 833 ◽  
pp. 28-32
Author(s):  
Xiao Teng Liu ◽  
Xiao Xu Zhu ◽  
Yu Zhen Zhao ◽  
Hai Hao
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Master Alloy ◽  
Az31 Alloy ◽  
Refining Process ◽  
The Self ◽  
Grain Structure ◽  
Temperature Synthesis ◽  
Refining Effect ◽  
High Temperature Synthesis

The Al-Ti-C master alloy with excessive carbon content was prepared by the self-propagating high-temperature synthesis (SHS) in melt method. The master alloy mainly contains Al4C3 and TiC phases, which exhibits satisfactory refining effect on AZ31 alloy. With 1.5wt.% addition of the master alloy, the grain size reduced from 280 μm to 109 μm. The tensile properties are also improved with the refinement of grain structure. The ultimate tensile strength increased from 105 MPa to 156 MPa while the elongation increased from 8.4% to 13.6%. The Al4C3 particles and TiC particles play important role in the refining process due to their low disregistry with α-Mg grains.

Structural-Phase State and Strength Properties of Pressure-Synthesized Ni3Al Intermetallic Compound

2017 ◽  
Vol 906 ◽  
pp. 95-100 ◽  
Author(s):  
V.E. Ovcharenko ◽  
E.N. Boyangin ◽  
A.P. Pshenichnikov ◽  
T.A. Krilova
Keyword(s):  
Grain Size ◽  
Intermetallic Compound ◽  
Powder Mixture ◽  
Delay Time ◽  
Phase State ◽  
Structural Phase ◽  
Strength Properties ◽  
Synthesis Product ◽  
Structural Phase State ◽  
High Temperature Synthesis

The article studies dependences of grain size in Ni3Al intermetallic compound synthesized under pressure in 3Ni+Al powder mixture in conditions of bulk exothermal reaction upon pre-pressure acting on the powder mixture and upon a delay time of applying pressure to a high-temperature synthesis product. It is proved that an increase in the pre-pressure on the parent powder mixture reduces the grain size, and an increase in the delay time increases the grain size in the synthesized intermetallic compound. Reducing the grain size from 10 to 1.75μm increases the strength of the intermetallic compound under pressure from 336 to 482 MPa (1.4 times).

Influence of Grain Size on Mechanical Properties in a Fe-9Ni-12Mn-2.5Si-1.0C TWIP Steel

2011 ◽  
Vol 197-198 ◽  
pp. 655-661
Author(s):  
Ze Bin Yang ◽  
Ding Yi Zhu ◽  
Wei Fa Yi ◽  
Shu Mei Lin ◽  
Cheng Mei Du
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Strain Hardening ◽  
Twip Steel ◽  
Optical Microscope ◽  
Coarse Grained ◽  
Microstructure Observation ◽  
Transmission Electron ◽  
Average Grain Size

We investigate the influence of grain size on mechanical properties in a Fe-9Ni-12Mn-2.5Si-1.0C TWIP steel by unidirectional tensile. Meanwhile the microstructures of the TWIP steel were observed and analyzed by optical microscope (OM) and transmission electron microscope (TEM). The experimental results show that the TWIP steel’s yield strength and tensile strength decrease with the increasing of grain size, whereas the plasticity increases with it. When the average grain size reaches to 27μm, the tensile strength is 1080MPa, the elongation percentage is 77%, and the strength-plasticity product achieves the 83160MPa•%. Steel’s strain hardening rate can be changed from three-stage to four-stage with the increasing of grain sizes, the areas of strain hardening by twin deformation mechanism are expanded. Through the microstructure observation we found that, coarse-grained TWIP steel conducts to twinning formation, the high density twins can increase the alloy’s ductility by splitting the grain.

Polycrystalline Grain Structure of Sputtered Aluminum Nitride Films

1994 ◽  
Vol 343 ◽  
Author(s):  
Asher T Matsuda ◽  
H. Ming Liaw ◽  
Wayne A Cronin ◽  
Harland G Tompkins ◽  
Peter L Fejes ◽  
...  
Keyword(s):  
Grain Size ◽  
Surface Morphology ◽  
Aluminum Nitride ◽  
Columnar Structure ◽  
Preferred Orientation ◽  
Grain Structure ◽  
Axis Orientation ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Acoustic Wave Devices

ABSTRACTReactively-sputtered, polycrystalline thin film aluminum nitride (AlN) is an attractive material for use in acoustic wave devices, for which it requires a strong preferred orientation, similar to that found in epitaxial films. This investigation evaluated the grain structure including preferred orientation, grain size, and surface morphology of sputtered A1N films. The characterization techniques utilized included x-ray diffraction (XRD), secondary ion mass spectroscopy (SIMS), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The results revealed two types of grain structure: 1) a single-grain columnar structure that is perfectly oriented in the [001] direction throughout the entire film thickness and 2) a multiple-grain columnar structure that possesses a strong [001] orientation at the bottom of the film and a tilted [001] combined with other orientations at the top of the film. Strong correlations between orientation and surface morphology, oxygen content, and grain size were observed, namely higher degrees of c-axis orientation correlated with lower mean surface roughness values, reduced oxygen concentration, and narrower grains.

Effect of Deformation Structure on Strength of a Low Alloyed Cu-Cr-Zr Alloy

2016 ◽  
Vol 879 ◽  
pp. 1332-1337 ◽  
Author(s):  
A. Morozova ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Strength Properties ◽  
Deformation Structure ◽  
Initial State ◽  
Continuous Dynamic Recrystallization ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Continuous Dynamic ◽  
Zr Alloy

The microstructure evolution and strength properties of a Cu-0.096%Cr-0.057%Zr alloy subjected to equal channel angular pressing (ECAP) at a temperature of 673 K via route BC to total strains of 1 to 4 were examined. The planar low-angle boundaries with moderate misorientations form within initial grains during the first ECAP passes. Upon further processing the misorientations of these boundaries progressively increase and the formation of new ultrafine grains occurs as a result of continuous dynamic recrystallization. Partially recrystallized ultrafine grained structure evolves at strains above 4. After straining to 4 the (sub) grain size attains 0.65 μm. The large plastic straining provides significant strengthening. The ultimate tensile strength increases from 190 MPa in the initial state to 420 MPa after 4 ECAP passes. A modified Hall-Petch analysis is applied to investigate the contribution of grain refinement and dislocation density to the overall strengthening.

scholarly journals Influence of Maximum Aggregate Grain Size on the Strength Properties and Modulus of Elasticity of Concrete

2020 ◽  
Vol 10 (11) ◽  
pp. 3918
Author(s):  
Jacek Góra ◽  
Małgorzata Szafraniec
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Modulus Of Elasticity ◽  
Maximum Size ◽  
Strength Properties ◽  
Building Structures ◽  
Grain Sizes ◽  
Deformation Properties ◽  
Strength And Deformation ◽  
Concrete Elements

Depending on the dimensions of concrete elements, aggregates of different grain sizes are used for the building structures. Taking this fact into account, the authors of the paper have undertaken in their work an issue concerning the analysis of the influence of maximum aggregate grain size on the strength properties and modulus of elasticity of concrete. This is also due to the fact that few published research results are available in this area. In this paper, the influence of the maximum grain size on the basic strength and deformation properties of concrete is discussed. The research concerns both concretes and gravel aggregates used for their construction with maximum grain sizes of 8 mm, 16 mm and 31.5 mm. The values of the compressive and splitting tensile strength, brittleness and modulus of elasticity of concretes with w/c = 0.45 were analysed. The analysis showed that the strength properties are proportional not only to the maximum size of aggregate grain, but also to the crushing strength of the aggregate. There were no analogous relations found with respect to the modulus of elasticity of the tested concretes. Tensile strength was particularly susceptible to the observed changes.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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