The Influence of Severe Plastic Deformation Process on Structure and Properties of AZ 31 Alloy after Selected Heat Treatment

2018 ◽  
Vol 275 ◽  
pp. 134-146
Author(s):  
Stanislav Rusz ◽  
Ondřej Hilšer ◽  
Stanislav Tylšar ◽  
Lubomír Čížek ◽  
Tomasz Tański ◽  
...  

The technology of structure refinement in materials with the aim of achieving substantial mechanical properties and maintaining the required plasticity level is becoming increasingly useful in industrial practice. Magnesium alloys are very progressive materials for utilization in practice thanks to their high strength-to-weight ratios (tensile strength/density). The presented paper analyses the effect of the input heat treatment of the AZ31 alloy on the change of structure and strength properties through the process of severe plastic deformation (SPD), which finds an increasing utilization, especially in the automotive and aviation industry. For the study of the influence of the SPD process (ECAP method) on the properties of the AZ31 alloy, two types of thermal treatment of the initial state of the structure were selected. The analysis of the structure of the AZ31 alloy was performed in the initial state without heat treatment and subsequently after heat treatment. In the next part, the influence of the number of passes on the strengthening curves was evaluated. Mechanical properties of the AZ31 alloy after ECAP were evaluated by hardness measurement and completed by structure analysis.

2014 ◽  
Vol 783-786 ◽  
pp. 842-847 ◽  
Author(s):  
Tibor Kvačkaj ◽  
Jana Bidulská

Nowadays, the strategy for improving of mechanical properties in metals is not oriented to alloying followed by heat treatment. An effective way how to improve the mechanical properties of metals is focused on the research looking for some additional structural abilities of steels. Structural refinement is one of the ways. Refinement of the austenitic grain size (AGS) carried out through plastic deformation in a spontaneous recrystallization region of austenite, formation of AGS by plastic deformations in a non-recrystallized region of austenite will be considered as potential ways for AGS refinement. After classic methods of plastic deformations, next structure refinement can be obtained by an application of severe plastic deformation (SPD) methods.


2012 ◽  
Vol 57 (3) ◽  
pp. 877-881 ◽  
Author(s):  
K. Wawer ◽  
M. Lewandowska ◽  
K.J. Kurzydłowski

In the present study, severe plastic deformation (SPD) processing was combined with pre- and post processing heat treatment to investigate the possibility of synergic grain size and precipitation strengthening. Samples of 7475 alloy were solution heat treated and water quenched prior to hydrostatic extrusion (HE) which resulted in a grain refinement by 3 orders of magnitude, from 70 μm to about 70 nm. The extruded samples were subsequently aged at temperatures resulting in formation of nanoprecipitates.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 296
Author(s):  
Irina Brodova ◽  
Dmitriy Rasposienko ◽  
Irina Shirinkina ◽  
Anastasia Petrova ◽  
Torgom Akopyan ◽  
...  

This paper identifies the mechanisms of phase and structural transformations during severe plastic deformation by shearing under pressure (high-pressure torsion) of an Al-Zn-Mg-Fe-Ni-based aluminum alloy depending on different initial states of the material (an ingot after homogenizing annealing and a rod produced by radial-shear rolling). Scanning and transmission electron microscopy are used to determine the morphological and size characteristics of the structural constituents of the alloy after high-pressure torsion. It has been found that, irrespective of the history under high-pressure torsion, fragmentation and dynamic recrystallization results in a nanostructural alloy with a high microhardness of 2000 to 2600 MPa. Combined deformation processing (high-pressure torsion + radial-shear rolling) is shown to yield a nanocomposite reinforced with dispersed intermetallic phases of different origins, namely Al9FeNi eutectic aluminides and MgZn2, Al2Mg3Zn3, and Al3Zr secondary phases. The results of uniaxial tensile testing demonstrate good mechanical properties of the composite (ultimate tensile strength of 640 MPa, tensile yield strength of 628 MPa, and elongation of 5%).


2020 ◽  
pp. 230-235
Author(s):  
A.A. Vasil’ev ◽  
S.P. Stetsenko ◽  
R.L. Vasilenko ◽  
D.G. Malykhin ◽  
P.I. Stoyev ◽  
...  

Studies were made into the effect of severe plastic deformation on the mechanical properties, structure, and texture of high-purity cast beryllium. For the first time, angular pressing of high-purity cast beryllium was carried out at temperatures of 600 and 500 °C. It is shown that the degree of grain refinement during angular pressing into a strip reaches a significant value. In a single deformation cycle, the grain is crushed from 3 mm down to 10 μm. Temperature dependences of the mechanical properties of the material of extruded billets in the initial state and after recrystallization annealing at a temperature of 650 °C for one hour were studied. It has been established that the best mechanical properties are shown by the samples of material deformed at 600 °C with subsequent annealing at 650 °C for an hour.


2021 ◽  
Vol 21 (4) ◽  
Author(s):  
M. B. Jabłońska ◽  
K. Kowalczyk ◽  
M. Tkocz ◽  
R. Chulist ◽  
K. Rodak ◽  
...  

AbstractThis paper presents some results of the influence of severe plastic deformation on the microstructure evolution, grain refinement aspect, and mechanical properties of ultra-low carbon steel. Ti-stabilized experimental IF steel was deformed at a room temperature with unconventional SPD process—dual rolls equal channel extrusion (DRECE). Mechanical properties and structure of ferritic steel in initial state and after selected steps of deformation were investigated. The mechanical properties were determined by static tensile tests carried out at a room temperature and microhardness research. The structural investigations involved using scanning transmission electron microscopy observations, electron back scattered diffraction and measurements of the crystallographic texture. The DRECE process affects the evolution of the structure. The microstructural investigations revealed that the processed strips exhibited a dislocation cell and grain structures with mostly low angle grain boundaries. The electron backscattering diffraction (EBSD) examination showed that the processed microstructure is homogeneous along the strips thickness. The mechanical properties of the DRECE-processed IF steel strips increased with an increase the number of passes.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1116
Author(s):  
Alena Michalcová ◽  
Dalibor Vojtěch ◽  
Jaroslav Vavřík ◽  
Kristína Bartha ◽  
Přemysl Beran ◽  
...  

Severe plastic deformation represented by three passes in Conform SPD and subsequent rotary swaging was applied on Ti grade 4. This process caused extreme strengthening of material, accompanied by reduction of ductility. Mechanical properties of such material were then tuned by a suitable heat treatment. Measurements of in situ electrical resistance, in situ XRD and hardness indicated the appropriate temperature to be 450 °C for the heat treatment required to obtain desired mechanical properties. The optimal duration of annealing was stated to be 3 h. As was verified by neutron diffraction, SEM and TEM microstructure observation, the material underwent recrystallization during this heat treatment. That was documented by changes of the grain shape and evaluation of crystallite size, as well as of the reduction of internal stresses. In annealed state, the yield stress and ultimate tensile stress decreased form 1205 to 871 MPa and 1224 to 950 MPa, respectively, while the ductility increased from 7.8% to 25.1%. This study also shows that mechanical properties of Ti grade 4 processed by continual industrially applicable process (Conform SPD) are comparable with those obtained by ECAP.


2013 ◽  
Vol 48 (13) ◽  
pp. 4705-4712 ◽  
Author(s):  
Jitka Vrátná ◽  
Miloš Janeček ◽  
Jakub Čížek ◽  
Dong Jun Lee ◽  
Eun Yoo Yoon ◽  
...  

2021 ◽  
Vol 43 (1) ◽  
pp. 1
Author(s):  
Agus Pramono ◽  
Suryana Suryana ◽  
Alfirano Alfirano ◽  
A. Ali Alhamidi ◽  
Adhitya Trenggono ◽  
...  

AbstrakProses produksi dengan menggunakan metode pengerjaan logam konvensional seringkali sulit terutama untuk produk masif, dimana peralatan dan produk seperti gaya dan tekanan tinggi diperlukan. Keterbatasan ini bisa diatasi dengan menggunakan teknologi terbaru yaitu severe plastic deformation (SPD), dengan metode spesifiknya yaitu equal channel angulatr pressing (ECAP). Perkembangan ECAP sudah mencapai tahap aplikasi produk, salah satu pengembangan metodenya yaitu model parallel channel, atau disebut ECAP-PC. Dalam aplikasi pembuatan komponen, diperlukan proses perlakuan panas material, bertujuan untuk mengubah sifat material. Perlakuan panas yang sesuai diantaranya adalah proses pelunakan anealling untuk pengerjaan komponen dan perlakuan panas jenis T6; artificial aging/age-hardening sebagai proses akhir, untuk penerapan aplikasi tertentu. Serbuk aluminium (Al) dengan campuran zirconium (Zr) diaktivasi secara mekanis menggunakan ball milling. Pencampuran menggunakan cairan etanol dan heptane untuk memudahkan pengeringan. Fraksi volume yang digunakan dalam komposit Al sebagai matriks dan Zr yaitu 97:3%. Serbuk komposit dilakukan penggilingan dengan proses ball milling menggunakan putaran 60 rpm selama 24 jam. Hasil perlakuan panas age-hardening menghasilkan sifat mekanik tertinggi sebesar 144-222 HV/1406-2177 MPa dibanding dengan jenis annealing yaitu 31-46 HV/301-449 MPa. Hal ini sesuai dengan tujuan dari perlakuan panas yaitu untuk menurunkan sifat mekanik agar material mudah diproses. AbstractThe production of conventional metalworking methods is often difficult especially for massive products, where equipment and products such as high force and pressure are required. This limitation can be overcome by using the latest technology, namely severe plastic deformation (SPD). By specific method, namely Equal Channel Angular Pressing (ECAP). The development of ECAP has reached the product application stage, one of the methods development is parallel channel model, or called ECAP-PC. Application of component manufacturing requires a material heat treatment process, aims to change the properties of the material. Suitable heat treatments include the annealing softening process for component work and the T6 type heat treatment; artificial aging/age-hardening as a finishing process for the application of certain applications. Aluminum (Al) powder and zirconium (Zr), mixture were activated mechanically by ball milling. Mixing processed using liquid ethanol and heptane for easy drying. The volume fraction used in the Al composite as a matrix and Zr is 97: 3%. The composites powder was milled by ball milling used a 60 rpm rotation for 24 hours. The results of age-hardening heat treatment produced the highest mechanical properties of 144-222 HV / 1406-2177 MPa compared to the type of annealing, namely 31-46 HV / 301-449 MPa. This is in accordance with the purpose of heat treatment, namely to reduce mechanical properties so that the material is easy to process.


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