Novel hexagonal structure and ultrahigh strength of magnesium solid solution in the Mg–Zn–Y system

2001 ◽  
Vol 16 (7) ◽  
pp. 1894-1900 ◽  
Author(s):  
Akihisa Inoue ◽  
Yoshihito Kawamura ◽  
Mitsuhide Matsushita ◽  
Kentaro Hayashi ◽  
Junichi Koike
Keyword(s):  
Solid Solution ◽  
Yield Strength ◽  
High Strain ◽  
High Strength ◽  
Hexagonal Structure ◽  
Tensile Yield Strength ◽  
Specific Yield ◽  
The Novel ◽  
Fine Grain ◽  
Novel Structure

A magnesium (Mg) solid solution with a long periodic hexagonal structure was found in a Mg97Zn1Y2 (at.%) alloy in a bulk form prepared by warm extrusion of atomized powders at 573 K. The novel structure has an ABACAB-type six layered packing with lattice parameters of a = 0.322 nm and c = 3 × 0.521 nm. The Mg solid solution has fine grain sizes of 100 to 150 nm and contains 0.78 at.% Zn and 1.82 at.% Y. In addition, cubic Mg24Y5 particles with a size of about 7 nm are dispersed at small volume fractions of less than 10% in the Mg matrix. The specific density (ρ) of the extruded bulk Mg–Zn–Y alloy was 1.84 Mg/m3. The tensile yield strength (σy) and elongation (δ) are 610 MPa and 5%, respectively, at room temperature, and the specific yield strength defined by the ratio of σy to ρ is as high as 3.3 × 105 Nm/kg. High σy values exceeding 400 MPa are also maintained at temperatures up to 473 K. It is noticed that the σy levels are 2.5 to 5 times higher than those for conventional high-strength type Mg-based alloys. The Mg-based alloy also exhibits a high-strain-rate superplasticity with large δ of 700 to 800% at high strain rates of 0.1 to 0.2 s−1 and 623 K. The excellent mechanical properties are due to the combination of the fine grain size, new long periodic hexagonal solid solution containing Y and Zn, and dispersion of fine Mg24Y5 particles. The new Mg-based alloy is expected to be used in many fields.

The Study on the Low Yield Strength for Super Fine Grain and High Strength Bearing Nb if Steel

2011 ◽  
Vol 335-336 ◽  
pp. 615-618
Author(s):  
Hong Mei Zhang ◽  
Li Feng Qiao
Keyword(s):  
Solid Solution ◽  
Yield Strength ◽  
Grain Boundary ◽  
High Strength ◽  
If Steel ◽  
Rolled Steel ◽  
Steel Sheets ◽  
Fine Grain ◽  
Cold Rolled ◽  
R Value

The cold rolling and simulative continuous annealing experiments after rolling were carried out in the laboratory on the base of super fine grain (SFG) steel sheet. The microstructure and the second-phase particles precipitated behavior were analyzed by the technology of OM, TEM and EDX. It is found that the fined Nb(C, N) can be formed by adding micro-alloy element Nb. It is noted that the yield strength is low as well as the tensile strength is high by the PFZ which is free of precipitate called precipitated free zone on the one side of the grain boundary. Contrast to the conventional IF steel, the super fine grain steel has super fine grains and gives excellent press-formability such as low yield strength, high r-value（the plastic strain ratio）. High strength cold-rolled steel sheets (HSS) with high formability have been developed in the last decade, in which the major strengthening method was solid-solution hardening with silicon, manganese and phosphorous [1-3]. When the IF steel is strengthened with the high amount of solid-solution elements, it becomes susceptible to the secondary work embrittlement because of the lack of grain boundary strength [4-6]. In this paper, High strength cold-rolled steel sheets (HSS) with high formability have been developed for the IF steel-bases. The grain refinement and precipitation hardening are achieved by means of the fine distribution of carbide under the appropriate combination of the relatively higher carbon content near 0.0070 mass% with niobium. As the result, this type of IF-HSS has been successfully developed to reach a higher r-value as compared with the conventional IF-HSS.

Effect of ZrB2 Nanoparticle Addition: Nano-LPSO-Grain Structured Ultra-High Strength Mg-RE Alloy

2014 ◽  
Vol 783-786 ◽  
pp. 425-430
Author(s):  
Muralidharan Paramsothy ◽  
Manoj Gupta
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Yield Strength ◽  
Polycrystalline Material ◽  
High Strength ◽  
Tensile Yield Strength ◽  
Intermetallic Formation ◽  
Long Period ◽  
Ordered Phases ◽  
The Common

Currently, long period stacking/ordered phases (LPSO phases) are known to reinforceMg97Y2Zn1 type Mg-RE alloys. The LPSO phases are composed of a solid solution of Y and Znatoms placed orderly in long periods along the Mg basal plane. Also, an efficient way to strengthena polycrystalline material is to reduce its grain size. This increases the density of grain boundarieswhich impede the flow of dislocations. In many of the LPSO forming solidification processed Mg-RE alloys, the common practice is to solutionize the ingot, quench in warm water, hot extrude andthermally age. While this practice is suitable for obtaining high strength Mg-RE alloys, itconveniently employs the common idea in conventional metallurgy of fine intermetallicstrengthening while refining the grain size to within the micron regime. In this work, an alternativemethod involving boride nanoparticle addition to obtain a selected solidification processed ultrahighstrength (tensile yield strength > 400 MPa) Mg-RE alloy is discussed. Here, LPSO phaserather than fine intermetallic formation while retaining grain size under the micron regime ishighlighted.

BETHLEHEM LUKENS PLATE SPARTAN

Alloy Digest ◽  
2003 ◽  
Vol 52 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Tensile Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Tensile Yield Strength ◽  
Precipitation Reactions

Abstract Bethlehem Lukens Plate (BLP) offers five grades of Spartan high-strength steels with tensile yield strength over 690 MPa (100 ksi). These alloys contain copper for precipitation reactions. They also have improved weldability and toughness compared to ASTM A 514 and A 543 grades. This datasheet provides information on composition, microstructure, hardness, and tensile properties as well as fracture toughness. It also includes information on forming and joining. Filing Code: SA-518. Producer or source: Bethlehem Lukens Plate.

Design of a novel HSLA steel with a combination of high strength (140–160 ksi) and excellent toughness

2021 ◽  
Vol 112 (10) ◽  
pp. 800-811
Author(s):  
Mehdi Soltan Ali Nezhad ◽  
Sadegh Ghazvinian ◽  
Mahmoud Amirsalehi ◽  
Amir Momeni
Keyword(s):  
Impact Toughness ◽  
Yield Strength ◽  
Hsla Steel ◽  
Charpy Impact ◽  
High Strength ◽  
Controlled Rolling ◽  
The Other ◽  
Grain Structure ◽  
Charpy Impact Toughness ◽  
Fine Grain

Abstract Three steels were designed based on HSLA-100 with additional levels of Mn, Ni, Cr and Cu. The steels were prepared by controlled rolling and tempered at temperatures in range of 550–700°C. The continuous cooling time curves were shifted to longer times and lower temperatures with the increased tendency for the formation of martensite at lower cooling rates. The microstructures revealed that controlled rolling results in austenite with uniform fine grain structure. The steel with the highest amount of Mn showed the greatest strength after tempering at 750 °C. The top strength was attributed to the formation of Cu-rich particles. The steel with 1.03 wt.% Mn, tempered at 650 °C exhibited the best Charpy impact toughness at –85°C. On the other hand, the steel that contained 2.11 wt.% Mn and tempered at 700 °C showed the highest yield strength of 1 097.5 MPa (∼159 ksi) and an impact toughness of 41.6 J at –85°C.

Deformation Mechanism of Nanocrystalline Al-Fe Alloys by Analysis from Ab-Initio Calculations

2006 ◽  
Vol 503-504 ◽  
pp. 209-214 ◽  
Author(s):  
Tokuteru Uesugi ◽  
Yorinobu Takigawa ◽  
Kenji Higashi
Keyword(s):  
Experimental Data ◽  
Solid Solution ◽  
Yield Strength ◽  
First Principles ◽  
High Strength ◽  
Misfit Strain ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Fe Alloys ◽  
Quench Method

Recently nanocrystalline Al-Fe alloys produced by a vapor quench method have been reported. These alloys are supersaturated solid solution and exhibit high strength with good ductility. It is postulated that the high strength of the Al-Fe alloys could be achieved by both the nano-grained structures and the solid solution strengthening. The contribution to the yield strength due to both the grain size strengthening and the solid solution strengthening were analyzed from the experimental data. Then the contribution to the yield strength due to the solid solution strengthening was estimated from the misfit strain calculated from the first principles in order to compare with analytical results estimated from the experimental data.

Nanocrystalline LPSO Mg-Zn-Y-Al Alloys with High Mechanical Strength and Corrosion Resistance

2010 ◽  
Vol 638-642 ◽  
pp. 1476-1481 ◽  
Author(s):  
Hitoshi Okouchi ◽  
Yoshikazu Seki ◽  
Takahiro Sekigawa ◽  
Hirohito Hira ◽  
Yoshihito Kawamura
Keyword(s):  
Corrosion Resistance ◽  
Fatigue Strength ◽  
Yield Strength ◽  
High Strength ◽  
Tensile Yield Strength ◽  
Alloy Development ◽  
High Mechanical Strength ◽  
Lpso Structure ◽  
Superior Mechanical Properties ◽  
Rapidly Solidified

Interests in magnesium alloys increase as eco-material for its lightweight, and many investigations have been carried out on the development of manufacturing processes and alloy development. In 2001, Mg97Zn1Y2 (at%) alloy with a tensile yield strength of 610 MPa and an elongation of more than 5 % has been developed by rapidly solidified powder metallurgy (RS P/M) processing. The developed alloy was characterized by a novel phase with long period stacking ordered (LPSO) structure. Recently, we have investigated new compositions for LPSO RS P/M Mg-Zn-Y-X alloys in order to improve the corrosion resistance of the RS P/M Mg97Zn1Y2 alloy with maintaining the superior mechanical properties. Consequently, we have developed a RS P/M Mg96.7Zn0.85Y2Al0.45 alloy with high strength and high corrosion resistance. The RS P/M Mg96.7Zn0.85Y2Al0.45 alloy contained the LPSO phase and exhibited a tensile strength of 525 MPa, an elongation of 9 % and a fatigue strength of 325 MPa, which were similar to those of the RS P/M Mg97Zn1Y2 alloy. However, the corrosion resistance of the RS P/M Mg96.7Zn0.85Y2Al0.45 alloy was 1.5 times that of the RS P/M Mg97Zn1Y2 alloy. The specific tensile yield strength, the specific fatigue strength and the corrosion resistance of the RS P/M Mg96.7Zn0.85Y2Al0.45 alloy were about 1.7 times, 1.8 times, and twice those of extra-super-duralumin (7075-T6 or 7075-T73), respectively.

scholarly journals The Research and Development of Safety Forewarning Composite Integral Strong Geocell

2015 ◽  
Vol 9 (1) ◽  
pp. 139-145
Author(s):  
Wang Qingbiao ◽  
Zhang Cong ◽  
Wen Xiaokang ◽  
Lü Rongshan ◽  
Xu Lei ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Yield Strength ◽  
Creep Test ◽  
Optimization Technique ◽  
High Strength ◽  
Economic Benefits ◽  
Tensile Yield Strength ◽  
Fiber Technology ◽  
New Type ◽  
The Relationship

In this paper, we have studied the high strength geocell development technology route, analyzed the rules of the tensile properties and creep properties of geocell, and established the relationship between elongation of stress and time, thus providing theoretical foundation for the development and engineering application of the new material. Through theoretical analysis, experimental research and numerical simulation, the characteristics, raw materials and craftsmanship of the geocell have been studied. The research is given on its stress and deformation rules based on elongation test and creep test. The rationality of the experiment is verified through numerical simulation and the conclusions are as follows: (1) With the research on the geocell traditional craftsmanship, combined with new technologies such as special ultrasonic welding technology, intelligent optical fiber technology and fixed locking plate technology, a new-type of safety forewarning high strength geocell can be developed. (2) Based on the geocell material characteristics, the elongation test and creep test are carried out and the tensile yield strength exceeds 250Mpa; the joint is welded by special crafts and the tensile strength ≥2000N/cm. (3) With FLAC3D numerical simulation, simulation study is performed on the mechanical properties of the new cell. Through analyzing the relationship between stress and strain, and time and displacement, the safety design and management construction of the new-type of geocell was proposed based on the actual situation of simulation. (4) The innovation points of the new-type of geocell include: the optimization technique of whole tensile yield strength, fall proof technique of lock parts, and positioning and effective monitoring technique, which effectively solves the geological problems of special projects such as ecological afforestation, sand fixation and high slope soft subgrade, and ensures the quality of the project and has high economic benefits.

INLAND HI-FORM

Alloy Digest ◽  
1978 ◽  
Vol 27 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Yield Strength ◽  
High Strength Steels ◽  
High Strength ◽  
Heat Treating ◽  
Low Carbon ◽  
Bending Properties ◽  
Fine Grain ◽  
Low Sulfur ◽  
Minimum Yield

Abstract INLAND HI-FORM Steels are a low-carbon, low or intermediate-manganese, low-sulfur, aluminum-killed, fine-grain, columbium and/or phosphorus-bearing series of high-strength steels providing greatly enhanced forming and bending properties. These steels are furnished in minimum yield strength levels from 40,000 to 80,000 psi. They are used widely in the transportation and mobile-equipment industries. See also Ispat Inland Cal Hi-Form 80Y100T, Alloy Digest CS-136, May 2003. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-346. Producer or source: Ispat Inland Inc..

High Strain Rate Tensile Behavior of Aluminum Alloy 7075 T651 and IS 2062 Mild Steel

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Jayaram R. Pothnis ◽  
Yernamma Perla ◽  
H. Arya ◽  
N. K. Naik
Keyword(s):  
Aluminum Alloy ◽  
Yield Strength ◽  
Mild Steel ◽  
High Strain Rate ◽  
Strain Rate ◽  
Strain Gauge ◽  
High Strain ◽  
Peak Force ◽  
Tensile Yield Strength ◽  
Aluminum Alloy 7075

Investigations on the effect of strain rate on tensile properties of two materials, namely, aluminum alloy 7075 T651 and IS 2062 mild steel, are presented. Experimental studies were carried out on tensile split Hopkinson pressure bar (SHPB) apparatus in the strain rate range of 54–164/s. Uncertainty analysis for the experimental results is presented. Johnson–Cook material constitutive model was applied to predict the tensile yield strength of the tested materials at different strain rates. It is observed that the tensile yield strength is enhanced compared with that at quasi-static loading. During tensile SHPB testing of the specimens, it was observed that the peak force obtained from the strain gauge mounted on the transmitter bar is lower than the peak force obtained from the strain gauge mounted on the incident bar. An explanation to this is provided based on the increase in dislocation density and necking in the tested specimens during high strain rate loading and the consequent stress wave attenuation as it propagates within the specimen. The fracture behavior and effect of high strain rate testing on microstructure changes are examined. The peak force obtained based on strain gauge mounted on the transmitter bar is lower than the peak force obtained based on strain gauge mounted on the incident bar. There is an increase in tensile yield strength at high strain rate loading compared with that at quasi-static loading for both materials. The enhancement is more for IS 2062 mild steel than that for aluminum alloy 7075 T651. In the range of parameters considered, the strength enhancement factor was up to 1.3 for aluminum alloy 7075 T651 and it was up to 1.8 for IS 2062 mild steel. Generally, there was a good match between the experimental values and the Johnson–Cook model predictions.

scholarly journals Ultrahigh specific strength in a magnesium alloy strengthened by spinodal decomposition

2021 ◽  
Vol 7 (23) ◽  
pp. eabf3039
Author(s):  
Tongzheng Xin ◽  
Yuhong Zhao ◽  
Reza Mahjoub ◽  
Jiaxi Jiang ◽  
Apurv Yadav ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Yield Strength ◽  
Spinodal Decomposition ◽  
Lattice Mismatch ◽  
High Strength ◽  
Specific Yield ◽  
Specific Strength ◽  
Dislocation Pinning ◽  
Solute Atoms ◽  
Engineering Alloys

Strengthening of magnesium (Mg) is known to occur through dislocation accumulation, grain refinement, deformation twinning, and texture control or dislocation pinning by solute atoms or nano-sized precipitates. These modes generate yield strengths comparable to other engineering alloys such as certain grades of aluminum but below that of high-strength aluminum and titanium alloys and steels. Here, we report a spinodal strengthened ultralightweight Mg alloy with specific yield strengths surpassing almost every other engineering alloy. We provide compelling morphological, chemical, structural, and thermodynamic evidence for the spinodal decomposition and show that the lattice mismatch at the diffuse transition region between the spinodal zones and matrix is the dominating factor for enhancing yield strength in this class of alloy.

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