scholarly journals Ultrafine-Grained Materials Fabrication with High Pressure Torsion and Simulation of Plastic Deformation Inhomogeneous Characteristics

2017 ◽  
Author(s):  
Yuepeng Song ◽  
Wenke Wang ◽  
Miaomiao Chen ◽  
Jing Guo ◽  
Lingfeng Xu ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
High Pressure Torsion ◽  
Ultrafine Grained ◽  
Ultrafine Grained Materials

The Processing of Ultrafine-Grained Materials Using High-Pressure Torsion

2007 ◽  
Vol 558-559 ◽  
pp. 1283-1294 ◽  
Author(s):  
Cheng Xu ◽  
Z. Horita ◽  
Terence G. Langdon
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
High Pressure ◽  
High Pressure Torsion ◽  
Metallic Materials ◽  
Grain Sizes ◽  
Ultrafine Grained ◽  
Wide Range ◽  
Ultrafine Grained Materials ◽  
Thin Disks

It is now well-established that processing through the application of severe plastic deformation (SPD) leads to a significant reduction in the grain size of a wide range of metallic materials. This paper examines the fabrication of ultrafine-grained materials using high-pressure torsion (HPT) where this process is attractive because it leads to exceptional grain refinement with grain sizes that often lie in the nanometer or submicrometer ranges. Two aspects of HPT are examined. First, processing by HPT is usually confined to samples in the form of very thin disks but recent experiments demonstrate the potential for extending HPT also to bulk samples. Second, since the strains imposed in HPT vary with the distance from the center of the disk, it is important to examine the development of inhomogeneities in disk samples processed by HPT.

Submicrocrystalline Austenitic Stainless Steel Processed by Cold or Warm High Pressure Torsion

2016 ◽  
Vol 838-839 ◽  
pp. 398-403 ◽  
Author(s):  
Marina Tikhonova ◽  
Nariman Enikeev ◽  
Ruslan Z. Valiev ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Severe Plastic Deformation ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Submicrocrystalline Structure ◽  
Ultrafine Grained ◽  
Different Temperatures

The formation of submicrocrystalline structure during severe plastic deformation and its effect on mechanical properties of an S304H austenitic stainless steel with chemical composition of Fe – 0.1C – 0.12N – 0.1Si – 0.95Mn – 18.4Cr – 7.85Ni – 3.2Cu – 0.5Nb – 0.01P – 0.006S (all in mass%) were studied. The severe plastic deformation was carried out by high pressure torsion (HPT) at two different temperatures, i.e., room temperature or 400°C. HPT at room temperature or 400°C led to the formation of a fully austenitic submicrocrystalline structure. The grain size and strength of the steels with ultrafine-grained structures produced by cold or warm HPT were almost the same. The ultimate tensile strengths were 1950 MPa and 1828 MPa after HPT at room temperature and 400°C, respectively.

The Flow Behavior of Ultrafine-Grained Materials

2014 ◽  
Vol 1013 ◽  
pp. 7-14
Author(s):  
Terence G. Langdon
Keyword(s):  
Plastic Deformation ◽  
High Pressure Torsion ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
High Strength ◽  
Flow Properties ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Small Grains ◽  
Ultrafine Grained Materials

Processing through the application of severe plastic deformation (SPD) leads to very significant grain refinement with grains that are typically in the submicrometer or even the nanometer range. These ultrafine-grained (UFG) materials provide an opportunity for achieving exceptional flow properties including high strength at ambient temperature and, if the very small grains are reasonably stable, superplastic elongations at high testing temperatures. These flow characteristics are examined for materials processed using the two SPD procedures of equal-channel angular pressing (ECAP) and high-pressure torsion (HPT).

Analysis of Plastic Deformation and Sample Geometry during the Compression Stage in High-Pressure Torsion

2014 ◽  
Vol 922 ◽  
pp. 592-597 ◽  
Author(s):  
Pedro Henrique R. Pereira ◽  
Túlio H.P. Costa ◽  
Roberto B. Figueiredo ◽  
Paulo Roberto Cetlin ◽  
Terence G. Langdon
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
High Pressure Torsion ◽  
Sample Thickness ◽  
Torsional Deformation ◽  
Initial Shape ◽  
Ultrafine Grained ◽  
Significant Interest ◽  
Small Grains ◽  
Compressive Pressure

The production of ultrafine-grained metals through severe plastic deformation (SPD) has attracted significant interest in the scientific community due to the improvement in mechanical properties. Among SPD methods, high pressure torsion (HPT) processing is most effective in producing exceptionally small grains in disc-shaped samples subjected to high hydrostatic pressures and concurrent torsional straining. The present paper analyzes the elastic distortions and plastic flow during the application of compressive pressure in samples during HPT. Simulations through finite element method reveal a distortion of the initial shape of the sample and a gradient in sample thickness between the center and the edge due to elastic distortions. Also, it is shown that significant plastic deformation takes place in this stage and this is before any torsional deformation is imposed on the sample.

Microstructure and Mechanical Properties of the SPD-Processed TiNi Alloys

2013 ◽  
Vol 738-739 ◽  
pp. 486-490 ◽  
Author(s):  
Dmitriy Gunderov ◽  
Alexandr Lukyanov ◽  
Egor Prokofiev ◽  
Anna Churakova ◽  
Vladimir Pushin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
Cold Rolling ◽  
High Pressure Torsion ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
First Results ◽  
Equal Channel Angular Pressure

The article represents results of influence of different severe plastic deformation (SPD) techniques on TiNi alloys. It is demonstrated that strength and shape memory effect (SME) of TiNi can be significantly enhanced due to formation of ultrafine-grained (UFG) and nanocrystalline (NC) structures by SPD. Influence of equal channel angular pressing (ECAP), high pressure torsion (HPT), multi-step SPD deformations (ECAP plus cold rolling) on structure, mechanical and functional properties of TiNi alloys is considered. There are represented first results of influence of equal channel angular pressure-Conform (ECAP-C) on TiNi alloys, which is a perspective technology for industrial fabrication of UFG metals and alloys.

Recrystallization and Grain Growth in Ultrafine-Grained Materials Produced by High Pressure Torsion

2010 ◽  
Vol 13 (4) ◽  
pp. 245-250 ◽  
Author(s):  
Anahita Khorashadizadeh ◽  
Dierk Raabe ◽  
Myrjam Winning ◽  
Reinhard Pippan
Keyword(s):  
High Pressure ◽  
Grain Growth ◽  
High Pressure Torsion ◽  
Ultrafine Grained ◽  
Ultrafine Grained Materials

GRAIN REFINEMENT AND MICROSTRUCTURE EVOLUTION IN ALUMINUM A2618 ALLOY BY HIGH-PRESSURE TORSION

2016 ◽  
Vol 78 (6-9) ◽  
Author(s):  
Intan Fadhlina Mohamed ◽  
Seungwon Lee ◽  
Kaveh Edalati ◽  
Zenji Horita ◽  
Shahrum Abdullah ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Grain Refinement ◽  
Room Temperature ◽  
Rotation Speed ◽  
High Pressure Torsion ◽  
Applied Pressure ◽  
Saturation Level ◽  
Microstructural Refinement ◽  
Average Grain Size

This work presents a study related to the grain refinement of an aluminum A2618 alloy achieved by High-Pressure Torsion (HPT) known as a process of Severe Plastic Deformation (SPD). The HPT is conducted on disks of the alloy under an applied pressure of 6 GPa for 1 and 5 turns with a rotation speed of 1 rpm at room temperature. The HPT processing leads to microstructural refinement with an average grain size of ~250 nm at a saturation level after 5 turns. Gradual increases in hardness are observed from the beginning of straining up to a saturation level. This study thus suggests that hardening due to grain refinement is attained by the HPT processing of the A2618 alloy at room temperature.

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