Mechanical behaviour and texture of annealed AZ31 Mg alloy deformed by ECAP
37
Citation
18
Reference
10
Related Paper
Citation Trend
Abstract:
AZ31 Mg alloy samples were processed by equal channel angular pressing (ECAP) at 220°C for four passes. An average grain size of ∼1·9 μm with reasonable homogeneity was obtained. The ECAP process imparted large plastic shear strains and strong deformation textures to the material. Subsequent annealing of the equal channel angular pressed samples produced interesting mechanical behaviours. While yield strength increased and ductility decreased immediately after undergoing ECAP, annealing at temperatures <250°C restored ductility significantly at a small decrease in of yield strength. Annealing at temperatures >250°C reduced yield strength without additional improvement in ductility. It is believed that the combination of stress relief via dislocation elimination, refined microstructure and the retention of a strong ECAP texture at low annealing temperatures enhance ductility. High temperature annealing breaks down the ECAP texture resulting in no further improvement in ductility. The results show that the mechanical properties of the alloy can be positively influenced by annealing after ECAP to achieve a combination of strength and ductility.Keywords:
Ductility (Earth science)
Severe Plastic Deformation
This study involves experimental investigation on severe plastic deformation (SPD) of Ti using novel equal-channel angular pressing (ECAP) at ambient temperature. Ti wire is tightly encapsulated in a hollow host material made of Al-based functionally graded material (FGM). The host material is prepared by embedding Al–Al 3 Ti alloy into Al. Three types of the Al–Al 3 Ti alloys with different Al 3 Ti volume fractions are used to prepare the host materials. ECAP for specimens is carried out for up to eight passes by route A. The microstructure and hardness of ECAPed specimens are investigated. The changes in microstructure and the increase in the hardness value of Ti with increased number of ECAP passes are evidences showing that Ti is successfully deformed by this technique.
Severe Plastic Deformation
Cite
Citations (1)
The paper proposes a new variation of the application of SPD methods. For the suggested TCMAP (twist channel multi angular pressing) technology a larger strain is imposed more effectively while homogeneity of material is increased. The number of passes needed to obtain the ultra-fine to nano-scale grains in bulk materials can be significantly reduced. Commercially pure Al (99.97%) was used for the experimental verification of the suggested process. The deformation parameters of the process were also described using a numerical simulation based on a FE analysis. The predicted value of imposed strain after a single pass reached approximately 2.7. Deformation homogeneity was confirmed by micro-hardness tests. Due to the designed shape of the channel both ends of the processed sample are defined by a higher imposed strain and vertical faces.
Cite
Citations (59)
Processing through the application of severe plastic deformation (SPD) has become important over the last decade because it is now recognized that it provides a simple procedure for producing fully-dense bulk metals with grain sizes lying typically in the submicrometer range. There are two major procedures for SPD processing. First, equal-channel angular pressing (ECAP) refers to the repetitive pressing of a metal bar or rod through a die where the sample is constrained within a channel bent through an abrupt angle at, or close to, 90 degrees. Second, high-pressure torsion (HPT) refers to the procedure in which the sample, generally in the form of a thin disk, is subjected to a very high pressure and concurrent torsional straining. Both of these processes are capable of producing metallic alloys with ultrafine grain sizes and with a reasonable degree of homogeneity. Furthermore, the samples produced in this way may exhibit exceptional mechanical properties including high strength at ambient temperature through the Hall-Petch relationship and a potential superplastic forming capability at elevated temperatures. This paper reviews these two procedures and gives examples of the properties of aluminum alloys after SPD processing.
Severe Plastic Deformation
Superplasticity
Accumulative roll bonding
Cite
Citations (0)
Compared with traditional processing methods, the severe plastic deformation (SPD) has some advantages. It can produce ultra-fine grain metals or alloys and has a strong impact on the microstructure and mechanical properties of materials. Three principal SPD methods, i.e. accumulative roll bonding, equal channel angular pressing, and high pressure and torsion, as well as the characteristics, present state and perspectives of SPD are summarized in this paper.
Severe Plastic Deformation
Accumulative roll bonding
Cite
Citations (0)
This work presents a study related to the achievement of a nanometric structure in AA3103, employing severe plastic deformation processes (SPD), in this case equal channel angular pressing (ECAP). The changes in the mechanical properties and in the microstructure of AA3103 were studied after being processed by ECAP. Subsequently, scanning electron microscopy was used to determine the evolution of the microstructure after different thermal treatments on the material processed by this severe plastic deformation process. Furthermore, a more profound knowledge of the changes in the mechanical properties of this aluminium alloy was obtained. It was demonstrated that with different appropriate combinations of thermal treatments and ECAP processing, it is possible to significantly improve the mechanical properties through obtaining submicrometric grain size structures.
Severe Plastic Deformation
Cite
Citations (2)
В данной статье рассматривается применение и технологии получения наноструктурированных поверхностей. Рассмотрены такие методы как компактирование порошков (изостатическое прессование, метод Гляйтера), интенсивная пластическая деформация (угловое кручение, равноканальное угловое прессование, обработка давлением многослойных композитов) и модификация поверхности (лазерная обработка, ионная бомбардировка). This article discusses the application and technology for obtaining nano-structured surfaces. Methods such as compaction of powders (isostatic pressing, Gleiter method), severe plastic deformation (angular torsion, equal-channel angular pressing, pressure treatment of multilayer composites) and surface modification (laser treatment, ion bombardment) are considered.
Severe Plastic Deformation
Surface Modification
Cite
Citations (0)
Equal channel angular pressing (ECAP), as one of the most feasible severe plastic deformation (SPD) techniques for industry manufacturing, can produce ultra-fine grained (UFG) structures and improve properties and forming ability of titanium alloys. The basic principle, research development and application of preparing UFG titanium alloys were introduced. The effects of different ECAP factors on microstructure and properties, and the micromechanism of grain refinement were analyzed. Finally, the problems and prospects were discussed.
Severe Plastic Deformation
Titanium alloy
Cite
Citations (0)
The commercially pure titanium cylindrical samples with a diameter of 11.5mm and a length of 24mm were processed by a new severe plastic deformation process, called the rotary-die equal channel angular pressing (RD-ECAP), under the condition of 773K, 2.4mm/s punch. By the RD-ECAP, ECAP processes of 1-4 passes were possible without sample removal and the temperature of cp-titanium could be simply controlled. After the RD-ECAP process, the cp-titanium samples had no crack. Fine-grained microstructures were observed in the sample on Y plane. Therefore the samples processed by RD-ECAP were expected to have high mechanical strength.
Severe Plastic Deformation
Cite
Citations (0)
This study involves experimental investigation on severe plastic deformation (SPD) of Ti using novel equal-channel angular pressing (ECAP) at ambient temperature. Ti wire is tightly encapsulated in a hollow host material made of Al-based functionally graded material (FGM). The host material is prepared by embedding Al–Al3Ti alloy into Al. Three types of the Al–Al3Ti alloys with different Al3Ti volume fractions are used to prepare the host materials. ECAP for specimens is carried out for up to eight passes by route A. The microstructure and hardness of ECAPed specimens are investigated. The changes in microstructure and the increase in the hardness value of Ti with increased number of ECAP passes are evidences showing that Ti is successfully deformed by this technique.
Severe Plastic Deformation
Cite
Citations (0)
Severe Plastic Deformation
Ductility (Earth science)
Cite
Citations (26)