scholarly journals Fracture and fracture toughness of nanopolycrystalline metals produced by severe plastic deformation

2015 ◽  
Vol 373 (2038) ◽  
pp. 20140366 ◽  
Author(s):  
A. Hohenwarter ◽  
R. Pippan
Keyword(s):  
Fracture Toughness ◽  
Plastic Deformation ◽  
Fracture Mechanics ◽  
Severe Plastic Deformation ◽  
Fracture Behaviour ◽  
Basic Research ◽  
Point Of View ◽  
Metallic Materials ◽  
Grain Sizes ◽  
Ultrafine Grained

The knowledge of the fracture of bulk metallic materials developed in the last 50 years is mostly based on materials having grain sizes, d , in the range of some micrometres up to several hundred micrometres regarding the possibilities of classical metallurgical methods. Nowadays, novel techniques provide access to much smaller grain sizes, where severe plastic deformation (SPD) is one of the most significant techniques. This opens the door to extend basic research in fracture mechanics to the nanocrystalline (NC) grain size regime. From the technological point of view, there is also the necessity to evaluate standard fracture mechanics data of these new materials, such as the fracture toughness, in order to allow their implementation in engineering applications. Here, an overview of recent results on the fracture behaviour of several different ultrafine-grained ( d <1 μm) and NC ( d <100 nm) metals and alloys covering examples of body- and face-centred cubic structures produced by SPD will be given.

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.

Mechanical and Functional Properties of Titanium Alloys Processed by Severe Plastic Deformation

2011 ◽  
Vol 683 ◽  
pp. 137-148 ◽  
Author(s):  
Vladimir V. Stolyarov
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Mechanical Behavior ◽  
Titanium Alloys ◽  
Functional Properties ◽  
Coarse Grained ◽  
Cyclic Loads ◽  
Metallic Materials ◽  
Ultrafine Grained

Systematized literature data related to the study of mechanical and functional properties of ultrafine-grained and nanostructured metallic materials processed by deformation methods are presented. Special attention is given to the mechanical behavior of titanium materials under tension, as well as under impact and cyclic loads. The advantage of the materials under investigation over their coarse-grained analogues is shown.

Influence of Annealing on the Structure and Mechanical Properties of Ultrafine-Grained Alloy Ti-6Al-7Nb, Processed by Severe Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 943-948 ◽  
Author(s):  
Veronika Polyakova ◽  
Irina P. Semenova ◽  
Ruslan Valiev
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Equal Channel Angular Pressing ◽  
Human Body ◽  
High Strength ◽  
Point Of View ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Strength And Ductility

This work is devoted to enhancement of strength and ductility of the Ti-6Al-7Nb ELI alloy, which is less harmful from medical point of view for human body in comparison to Ti-6Al-4V. It has been demonstrated that formation of an ultrafine-grained structure in the alloy with the help of equal-channel angular pressing in combination with heat and deformation treatments allows reaching high strength (UTS = 1400 MPa) and sufficient ductility (elongation 10 %).

scholarly journals Влияние термообработки на упругие и микропластические свойства ультрамелкозернистого титана с разным содержанием примесей

2019 ◽  
Vol 45 (22) ◽  
pp. 47
Author(s):  
Б.К. Кардашев ◽  
М.В. Нарыкова ◽  
В.И. Бетехтин ◽  
А.Г. Кадомцев ◽  
А.Ю. Токмачева-Колобова
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Elevated Temperatures ◽  
Impurity Content ◽  
Grain Sizes ◽  
Ultrafine Grained ◽  
Titanium Grade ◽  
Thermal Stability Of

The effect of elevated temperatures on elastic and microplastic properties of ultrafine-grained titanium prepared by severe plastic deformation is discussed. Three sets of a-titanium VT1-0, Grade-4 and PT3-V which differ each other in polycrystal structure and impurity content were investigated. As experiments show, significant changes in grain sizes, elastic and microplastic properties were observed only for the purest titanium VT1-0. The thermal stability of other sets of titanium (Grade-4 and PT3-V) was found to be better; it is explained by higher impurity content in these materials.

Mechanical Behaviors of Ultrafine Grained Metallic Materials

2007 ◽  
Vol 124-126 ◽  
pp. 1325-1328
Author(s):  
Dong Hyuk Shin ◽  
Duck Young Hwang ◽  
Jung Yong Ahn ◽  
Kyung Tae Park ◽  
Yong Suk Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Coarse Grained ◽  
Metallic Materials ◽  
Room Temperature Ductility ◽  
Ultrafine Grained ◽  
Superior Mechanical Properties ◽  
Ultrafine Grained Materials ◽  
The Relationship

Ultrafine grained materials fabricated by severe plastic deformation exhibit both superior and inferior mechanical properties, as the prominent structural materials, compared to coarse grained counterparts. The superior mechanical properties are ultrahigh strength and exceptional ductility at high temperatures (i.e., superplasticity). The inferior mechanical properties are lack of strain hardenability and room temperature ductility. In this study, the relationship between microstructure and mechanical properties of ultrafine grained materials fabricated by severe plastic deformation is investigated in order to provide insight broadening their future applicability.

Extending Creep and Superplasticity to Materials with Submicrometer Grain Sizes

2007 ◽  
Vol 345-346 ◽  
pp. 539-544
Author(s):  
Megumi Kawasaki ◽  
Cheng Xu ◽  
Z. Horita ◽  
Terence G. Langdon
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloys ◽  
Severe Plastic Deformation ◽  
Flow Behavior ◽  
Ultrafine Grain ◽  
Grain Sizes ◽  
Large Samples ◽  
Angular Pressing ◽  
Recent Advances ◽  
Ultrafine Grained

The mechanisms of creep and superplasticity occurring in conventional large-grained materials are now understood reasonably well. However, very recent advances in the processing of theoretically-dense metals with submicrometer grain sizes have provided the opportunity to extend the understanding of flow behavior to include materials where the grains are exceptionally small. Using processing through the application of severe plastic deformation, as in procedures such as equal-channel angular pressing, it is now feasible to fabricate relatively large samples having ultrafine grain sizes in the submicrometer or nanometer range. This paper examines these recent advances and gives examples of the flow behavior in ultrafine-grained aluminum alloys.

Strain Compatibility and Nanostructuring of Bulk Metallic Materials via Severe Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 45-49
Author(s):  
Farid Z. Utyashev
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Elevated Temperatures ◽  
High Strength ◽  
Deformation Mode ◽  
Point Of View ◽  
Metallic Materials ◽  
Strain Compatibility ◽  
Structural Applications ◽  
Superplastic Properties

Nanostructured (NS) metallic materials can exhibit high strength at room temperature and superplastic properties at elevated temperatures. This enables to enhance their technological and structural properties, when producing various parts from them. For producing NS materials by severe plastic deformation (SPD), the development of effective SPD techniques for practical use is an urgent task. It is shown that solution of such a task should take into account strain compatibility on the macro-, meso- and micro-levels. Not only shear but also rotational deformation mode should be considered. Properties of NS materials and possibilities of their structural applications are considered from this point of view.

Sign in / Sign up

Export Citation Format

Share Document