Microstructures and Mechanical Behavior of Bulk Nanocrystalline γ–Ni–Fe Produced by a Mechanochemical Method

2002 ◽  
Vol 17 (5) ◽  
pp. 991-1001 ◽  
Author(s):  
X. Y. Qin ◽  
J. S. Lee ◽  
C. S. Lee
Keyword(s):  
Yield Strength ◽  
Mechanical Behavior ◽  
Light Emission ◽  
Hot Isostatic Pressing ◽  
Microstructural Analysis ◽  
High Strength ◽  
Compression Tests ◽  
Mechanochemical Method ◽  
Force Microscopy ◽  
Bulk Nanocrystalline

The microstructures and mechanical behavior of bulk nanocrystalline γ–Ni–xFe (n-Ni–Fe) with x = ∼19–21 wt%, synthesized by a mechanochemical method plus hot-isostatic pressing, were investigated using microstructural analysis [x-ray diffraction, energy-dispersive spectroscopy, light emission spectrum, atomic force microscopy (AFM), and optical microscopy (OM)], and mechanical (indentation and compression) tests, respectively. The results indicated that the yield strength (σ0.2) of n-Ni–Fe (d ∼ 33 nm) is about 13 times greater than that of conventional counterpart. The change of yield strength with grain size was basically in agreement with Hall–Petch relation in the size range (33–100 nm) investigated. OM observations demonstrated the existence of two sets of macroscopic bandlike deformation traces mostly orienting at 45–55° to the compression axis, while AFM observations revealed that these bandlike traces consist of ultrafine lines. The cause for high strength and the possible deformation mechanisms were discussed based on the characteristics of microstructures and deformation morphology of n-Ni–Fe.

Paradox of Strength and Ductility in Metals Processed Bysevere Plastic Deformation

2002 ◽  
Vol 17 (1) ◽  
pp. 5-8 ◽  
Author(s):  
R. Z. Valiev ◽  
I. V. Alexandrov ◽  
Y. T. Zhu ◽  
T. C. Lowe
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Yield Strength ◽  
Mechanical Behavior ◽  
High Strength ◽  
High Ductility ◽  
Elongation To Failure ◽  
Failure Ductility ◽  
Strength And Ductility

It is well known that plastic deformation induced by conventional forming methodssuch as rolling, drawing or extrusion can significantly increase the strength of metalsHowever, this increase is usually accompanied by a loss of ductility. For example, Fig.1 shows that with increasing plastic deformation, the yield strength of Cu and Almonotonically increases while their elongation to failure (ductility) decreases. Thesame trend is also true for other metals and alloys. Here we report an extraordinarycombination of high strength and high ductility produced in metals subject to severeplastic deformation (SPD). We believe that this unusual mechanical behavior is causedby the unique nanostructures generated by SPD processing. The combination ofultrafine grain size and high-density dislocations appears to enable deformation by newmechanisms. This work demonstrates the possibility of tailoring the microstructures ofmetals and alloys by SPD to obtain both high strength and high ductility. Materialswith such desirable mechanical properties are very attractive for advanced structuralapplications.

scholarly journals Cyclic Deformation of Advanced High-Strength Steels: Mechanical Behavior and Microstructural Analysis

2009 ◽  
Vol 40 (2) ◽  
pp. 342-353 ◽  
Author(s):  
Timothy B. Hilditch ◽  
Ilana B. Timokhina ◽  
Leigh T. Robertson ◽  
Elena V. Pereloma ◽  
Peter D. Hodgson
Keyword(s):  
Mechanical Behavior ◽  
Cyclic Deformation ◽  
Microstructural Analysis ◽  
High Strength Steels ◽  
High Strength ◽  
Advanced High Strength Steels

Synthesis and Characterization of Mechanically Alloyed and HIP-Consolidated Fe-25Al-10Ti Intermetallic Alloy

2000 ◽  
Vol 646 ◽  
Author(s):  
Su-Ming Zhu ◽  
Makoto Tamura ◽  
Kazushi Sakamoto ◽  
Kunihiko Iwasaki
Keyword(s):  
Yield Strength ◽  
Tribological Properties ◽  
Room Temperature ◽  
Hot Isostatic Pressing ◽  
Microstructural Characterization ◽  
Intermetallic Alloy ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Positive Temperature ◽  
Compression Tests

ABSTRACTThe present study is concerned with the processing, microstructural characterization, mechanical and tribological properties of fine-grained Fe-25Al-10Ti intermetallic alloy. The alloy was synthesized from elemental powders by mechanical alloying in an attritor-type ball milling system for 100 h, followed by hot isostatic pressing (HIP). After HIP treatment at 1073 K under an ultra-high pressure of 980 MPa, fully dense compacts with a grain size of about 200 nm were produced. Mechanical properties were evaluated by compression tests from room temperature to 1073 K. At room temperature, the alloy exhibits yield strength as high as 2.4 GPa, together with considerable rupture strain of 0.16. The yield strength decreases monotonically with increasing test temperature with no positive temperature dependence observed. The grain growth after high temperature deformation is not severe, indicating that the alloy has a relatively high thermal stability. Finally, tribological properties of the alloy were evaluated by using a ball-on-disk type wear tester and compared with those for gray cast iron, a currently used material for automotive brake rotors.

Effect of Tempering Temperature on Microstructure, Texture and Mechanical Properties of a High Strength Steel

2014 ◽  
Vol 4 (3) ◽  
pp. 33-49 ◽  
Author(s):  
Pradipta Kumar Jena ◽  
K. Siva Kumar ◽  
A.K. Singh
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Mechanical Behavior ◽  
High Strength Steel ◽  
High Strength ◽  
Tempering Temperature ◽  
Plane Anisotropy ◽  
Microstructures And Mechanical Properties

This work describes the microstructure, texture and anisotropy in mechanical behavior of a high strength steel in various tempered conditions. The microstructures and mechanical properties change considerably with varying tempering temperatures. The material exhibits low in-plane anisotropy and low anisotropic index in terms of yield strength and elongation with increase in tempering temperature. The anisotropy of the material displays similar behavior to that of the yield strength.

Effect of Tempering Temperature on Microstructure, Texture and Mechanical Properties of a High Strength Steel

2017 ◽  
pp. 1690-1702
Author(s):  
Pradipta Kumar Jena ◽  
K. Siva Kumar ◽  
A.K. Singh
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Mechanical Behavior ◽  
High Strength Steel ◽  
High Strength ◽  
Tempering Temperature ◽  
Plane Anisotropy ◽  
Microstructures And Mechanical Properties

This work describes the microstructure, texture and anisotropy in mechanical behavior of a high strength steel in various tempered conditions. The microstructures and mechanical properties change considerably with varying tempering temperatures. The material exhibits low in-plane anisotropy and low anisotropic index in terms of yield strength and elongation with increase in tempering temperature. The anisotropy of the material displays similar behavior to that of the yield strength.

Production of High Nitrogen Stainless Steel X8CrMnN18-18 through EAF-AOD-LRF-CC-Steckel Mill Route and its Hot Deformation Study by Gleeble Thermomechanical Simulator

2013 ◽  
Vol 794 ◽  
pp. 429-440
Author(s):  
Sudipta Patra ◽  
Lokesh Kumar Singhal
Keyword(s):  
Stainless Steel ◽  
Grain Refinement ◽  
Hot Deformation ◽  
Microstructural Analysis ◽  
High Strength ◽  
Microstructural Characterization ◽  
Mechanical Processing ◽  
Compression Tests ◽  
High Nitrogen ◽  
High Nitrogen Stainless Steel

High nitrogen containing austenitic stainless steel X8CrMnN18-18 exhibits attractive combination of high strength, toughness and corrosion resistance.This grade containing more than 5000 ppm of nitrogen was produced commercially through EAF-AOD-LRF-CC-Steckel mill route and its microstructure and mechanical properties were studied. Excellent combination of strength,ductility and toughness is achieved in the entire range of 6mm to 50mm thick hot rolled plates. Uniaxial compression tests were carried out to understand the hot deformation behavior by varying temperature and strain rate. Softening behavior during deformation was analyzed from flow stress strain curves and microstructural analysis. Dynamic recrystallization (DRX) behavior of the material was observed during thermo mechanical processing. Critical strain related to DRX and Avrami kinetics of DRX was calculated by analyzing the flow curve data. Microstructural characterization was done by optical microscopy and EBSD analysis. Extensive grain refinement can be achieved by thermo-mechanical processing controlled by DRX. Keywords: High nitrogen stainless steel, Strength and toughness, DRX, Grain refinement, TMCP

Research of Anti-Extrusion Process for Cylinder of Spray-Formed Ultra-High Strength Aluminum Alloy

2014 ◽  
Vol 633-634 ◽  
pp. 103-107
Author(s):  
Shu Hui Huang ◽  
Zhi Hui Li ◽  
Bai Qing Xiong ◽  
Yong An Zhang ◽  
Xi Wu Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Hot Isostatic Pressing ◽  
High Strength ◽  
Extrusion Process ◽  
Compression Tests ◽  
Homogenization Treatment ◽  
High Strength Aluminum Alloy ◽  
Strain Relationship ◽  
The Common

Anti-extrusion process for the cylinder of spray-formed ultra-high strength aluminum alloy is researched in this paper. The spray-formed 7xxx aluminum alloy is treated by a two-step homogenization treatment (440 °C / 12h + 472 °C / 24h) after hot isostatic pressing (HIP), and then hot compression tests are carried out for getting the stress-strain relationship under different forming conditions. Anti-extrusion process for the cylinder is improved including changing the shape of mould and billet, and numerical simulation is used for researching the anti-extrusion process. According to the distribution of strain-effective, it can be seen that the improved scheme of anti-extrusion process can get more deformation than the common scheme at the bottom. The result of anti-extrusion experiments shows that the microstructure is evenly distributed across the cylinder under the improved scheme.

scholarly journals Effect of Nb and Mo Additions in the Microstructure/Tensile Property Relationship in High Strength Quenched and Quenched and Tempered Boron Steels

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 29
Author(s):  
Irati Zurutuza ◽  
Nerea Isasti ◽  
Eric Detemple ◽  
Volker Schwinn ◽  
Hardy Mohrbacher ◽  
...  
Keyword(s):  
Yield Strength ◽  
Tensile Properties ◽  
Hot Rolling ◽  
Synergetic Effect ◽  
High Strength ◽  
Carbon Steels ◽  
Compression Tests ◽  
Tempering Treatment ◽  
Microalloying Elements ◽  
Boron Steels

Recently, advanced thermomechanical hot rolling schedules followed by direct quenching are being developed in order to avoid reheating and quenching treatment after hot rolling to eliminate an energy and cost consuming step. The use of boron as an alloying element is a widely known practice in high strength medium carbon steels to increase the strength due its potential for delaying phase transformation and improving hardenability. In addition, a significant synergetic effect on hardenability could be reached combining B with microalloying elements (adding Nb, Mo or Nb-Mo). With the purpose of exploring the effect of microalloying elements and thermomechanical rolling schedule, laboratory thermomechanical simulations reproducing plate mill conditions were performed using ultra high strength steels micro-alloyed with Nb, Mo, and Nb-Mo. To that end, plane compression tests were performed, consisting of an initial preconditioning step, followed by several roughing and finishing deformation passes and a final quenching step. After fast cooling to room temperature, a tempering treatment was applied. In the present paper, the complex interaction between the martensitic microstructure, the tempering treatment, the addition of microalloying elements, and the resulting tensile properties was evaluated. For that purpose, an exhaustive EBSD quantification was carried out in both quenched as well as quenched and tempered states for all the steel grades and the contribution of different strengthening mechanisms on yield strength was analyzed. Highest tensile properties are achieved combining Nb and Mo, for both quenched (Q) and quenched and tempered states (Q&T), reaching yield strength values of 1107 MPa and 977 MPa, respectively. Higher tempering resistance was measured for the Mo-bearing steels, making the CMnNbMoB steel the one with the lowest softening after tempering. For CMnB grade, the yield strength reduction after tempering of about 413 MPa was measured, while for NbMo micro-alloyed steel, yield strength softening is considerably reduced to 130 MPa.

DOGAL LAD

Alloy Digest ◽  
2011 ◽  
Vol 60 (10) ◽  
Keyword(s):  
Yield Strength ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
High Strength ◽  
Heat Treating ◽  
Minimum Yield

Abstract Dogal 300 LAD, 340 LAD, 380 LAD, 420 LAD, 460 LAD and 500 LAD are high-strength low alloyed steels intended for pressing. The designation in the name is the guaranteed minimum yield strength. Dogal steels can be zinc coated. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on surface qualities as well as forming, heat treating, joining, and surface treatment. Filing Code: CS-167. Producer or source: SSAB Swedish Steel Inc..

RUUKKI RAEX 300

Alloy Digest ◽  
2012 ◽  
Vol 61 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Shear Strength ◽  
Impact Toughness ◽  
Yield Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Strength ◽  
Structural Components ◽  
Wear Resistant

Abstract RUUKKI RAEX 300 (typical yield strength 900 MPa) is part of the Raex family of high-strength and wear-resistant steels with favorable hardness and impact toughness to extend life and decrease wear in structural components. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness. It also includes information on wear resistance as well as forming, machining, and joining. Filing Code: SA-643. Producer or source: Rautaruukki Corporation.

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