Investigation of texture development and Portevin-Le Chatelier bands in 5754 aluminum alloy

Download

index.pdf

Date

2019

Author

Aytuna, Orhan Berk

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

320
views

185
downloads

Texture and microstructure are substantial parameters for final products which are made of non-heat treatable aluminum alloys such as 5xxx series. Optimizing these parameters is possible via deformation processes and following heat treatments. In this thesis; hot and cold rolling operation, as a basic deformation process, was applied to the aluminum and resulting copper, brass and cube type of texture was investigated. Effects of different annealing parameters on the deformed specimens were also analyzed with texture development and microstructural features such as recrystallization and abnormal grain growth. It was also detected that mechanical behavior of this alloy was also affected by nucleation and propagation of Portevin-Le Chatelier bands under various strain paths. Therefore, an in-plane biaxial test apparatus was utilized with a miniature cruciform specimen to achieve uniaxial and equibiaxial strain paths. The magnitude of load serrations and inhomogeneous strain distributions due to PLC effect were examined with load cells and digital image correlation technique, respectively. Under biaxial stretching, PLC bands nucleated and propagated repeatedly at the same region of the specimen, while their formation was random under uniaxial tension. Due to shear stresses in uniaxial tension, PLC bands were promoted and evolved into sharp visible shear bands which cause eventual failure of product. Texture analysis also confirmed the emergence of shear components and cube texture with increasing strain. Conversely, biaxial deformation conditions were beneficial for prevention of undesired fracture from shear bands even if PLC strain contribution to the total strain was higher than uniaxial conditions.

Subject Keywords

Aluminum alloys, Aluminum alloys Metallurgy., PLC, DIC, Biaxial, Forming, Texture.

URI

http://etd.lib.metu.edu.tr/upload/12624753/index.pdf
https://hdl.handle.net/11511/44746

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Analysis of magnesium addition, hydrogen porosity and T6 heat treatment effects on mechanical and microstructural properties of pressure die cast 7075 aluminum alloy Alat, Ece; Kalkanlı, Ali; Department of Metallurgical and Materials Engineering (2012) Aluminum alloys are having more attention due to their high specific stiffness and processing advantages. 7075 aluminum alloy is a wrought composition aluminum alloy in the Al-Zn-Mg-Cu series. Due to the significant addition of these alloying elements, 7075 has higher strength compared to all other aluminum alloys and effective precipitation hardenability characteristic. On the other hand, aluminum alloys have some drawbacks, which hinder the widespread application of them. One of the most commonly encounte...
Investigation of Portevin-LeChatelier Bands in 5754 Aluminum Alloy under Various Strain Paths Aytuna, O. Berk; Efe, Mert (Elsevier BV; 2019-01-01) This work investigated the mechanical and microstructural effects of Portevin-LeChatelier bands in aluminum 5754 alloy under different loading conditions. For these conditions (equibiaxial and uniaxial), an in-plane biaxial test apparatus was utilized with a miniature cruciform specimen. The amount and magnitude of load jumps and drops (serrations) due to the PLC bands were monitored by load cells and strain distributions were measured by digital image correlation technique. Under biaxial stretching, PLC ba...
Production and heat treatment of 6111 aluminum alloy sheet for car body panel application Sevimli, Aylin; Kalkanlı, Ali; Department of Metallurgical and Materials Engineering (2015) Aluminum is one of the major candidates to supply sufficient weight reduction without missing mechanical properties and performance. Therefore, studies have been focused on improving properties of aluminum in automotive application since 1920s. Heat treatable aluminum alloy are used in car body panels of automotive application such as 2xxx, 7xxx and 6xxx series aluminum alloys base on the mechanical properties. On the other hand, based on physical and economical properties 6xxx series aluminum alloys are wi...
Investigation of SiCp reinforced aluminium matrix composites by shear and longitudinal ultrasonic waves Gür, Cemil Hakan (2001-11-01) SiC particulate reinforced aluminium matrix composites are attractive materials for automotive and aerospace applications because of their outstanding stiffness and strength as compared to the aluminium alloys, in addition to the low cost of particulate reinforcement. The aim of this study is to establish correlations between ultrasonic wave velocities and SiC content, microstructure and mechanical properties of SiC reinforced Al composites, Specimens were fabricated for various volume fraction and size com...
Effect of welding parameters on the hot cracking behavior of 7039 aluminum - zinc alloy Akkuş, Mert; Gürbüz, Rıza; Batıgün, Caner; Department of Metallurgical and Materials Engineering (2010) 7039 aluminum alloys are widely being used in the aerospace, automotive and defense industries in which welding technique is used for their joining. The main problem encountered during the welding of 7039 aluminum alloy is hot cracking. The aim of this study is to understand the effect of welding parameters on the hot cracking behavior of 7039 aluminum alloy by using Modified Varestraint Test (MVT) with Gas Tunsgten Arc Welding (GTAW) technique. During tests, welding speed was selected as varying parameter,...

Citation Formats

O. B. Aytuna, “Investigation of texture development and Portevin-Le Chatelier bands in 5754 aluminum alloy,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Metallurgical and Materials Engineering., Middle East Technical University, 2019.