Large strain and small-scale biaxial testing of sheet metals

Download
index.pdf
2016
Seymen, Yadigar
Show full item record
199
views
316
downloads
Small-scale and multi-axial testing of sheet metals, particularly of lightweight alloys and advanced high strength steels (AHSS) are becoming important as these materials exhibit forming behavior sensitive to their unique microstructural features and strain paths. As an alternative to large-scale standard tests, in this study, a novel biaxial tensile test apparatus for miniature cruciform samples is introduced. The compact and portable apparatus includes a custom-built optical microscope and high-resolution digital imaging and correlation equipment for in-plane and in-situ strain measurements at the microstructure scale. The small strain and premature fracture problems common to the cruciform tests are solved by optimizing the sample design and by meticulously controlling the manufacturing steps and surface finish. Strain analyses reveal a key mechanism responsible for large strains and fracture at the center. This mechanism suppresses the local neck formation and allows uniform deformation under equibiaxial conditions until fracture. When normalized with the strain hardening exponent of the sample material (Al 6061-T6), the effective strain value before fracture, , surpasses the reported values for similar materials tested by cruciform and standard methods.
Sheet-metal., Metals, Metals, Strains and stresses., Strength of materials.
http://etd.lib.metu.edu.tr/upload/12620110/index.pdf
https://hdl.handle.net/11511/25747
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Large Strain and Small-Scale Biaxial Testing of Sheet Metals
Seymen, Y.; Güler, Baran; Efe, Mert (2016-11-01)
Small-scale and multi-axial testing of sheet metals, particularly of lightweight alloys and advanced steels are becoming important as these materials exhibit forming behavior sensitive to their unique microstructural features and strain paths. As an alternative to large-scale standard tests, in this paper we introduce a novel biaxial tensile test apparatus utilizing miniature cruciform samples. The compact and portable apparatus includes a custom-built optical microscope and high-resolution digital image co...
Production of in situ aluminum-titanium diboride master alloy formed by slag-metal reaction
CHANGIZI, Ahmad; Kalkanlı, Ali; SEVINC, NACİ (Elsevier BV, 2011-01-12)
Al-TiB(2) master alloys have received much attention in recent years owing to their potential as efficient grain refiners for aluminum foundry alloys. In this study, the process of production of master alloys was investigated to develop a low cost method, namely, slag-metal reaction. This method can be used to fabricate Al-TiB2 master alloy in situ from the TiO(2)-H(3)BO(3)-Na(3)AlF(6) and Al system. Since the price of the raw materials is low and the technology is simple, the processing technique appears t...
Experimental determination of tool wear in routing and trimming of CFRP composites
Peker, Zühal; Akkök, Metin; Kılıç, S. Engin; Department of Mechanical Engineering (2015)
In order to fulfill growing demand for lighter aircraft, Carbon fiber reinforced polymers (CFRP) have been developed, which differ from metals with regards to their machinability characteristics. The main problem in machining process is the damage caused by delamination of CFRP materials which need to be both cut and shorn of fibers at the same time, since they are remarkably abrasive in nature. This research aims at accessing the most appropriate cutting condition with less tool wear in routing and trimmin...
Long-term thermal stability of Equal Channel Angular Pressed 2024 aluminum alloy
TAN, Guher; Kalay, Yunus Eren; Gür, Cemil Hakan (2016-11-20)
The strength of bulk metallic materials can be improved by creating ultra-fine grained structure via severe plastic deformation (SPD). However, the thermal stability of severely deformed materials has been a major issue that restricts their practical use within the industry. Although there are studies on the thermal stability of SPD metals, the long-term annealing response of particularly complex alloys, such as the age hardenable ones, remains undetermined. In the present study, annealing behavior of the s...
Synthesis and characterization of copper based bulk amorphous alloys
Erdem, Mermer; Akdeniz, Mahmut Vedat; Mekhrabov, Amdulla O.; Department of Metallurgical and Materials Engineering (2013)
Copper based bulk metallic glasses (BMG’s) are one of the promising advanced materials due to their unique mechanical properties, high glass forming ability (GFA) and low cost. In this thesis, the aim is to synthesize Cu-Hf based BMG’s and to investigate the crystallization behavior. Moreover, the crystallization kinetics by means of activation energies, critical cooling rate, nanocrystallization and Avrami exponents have been studied. Cu70Hf30 and Cu50Hf50 binary alloys were produced via arc melting with s...
Citation Formats
Y. Seymen, “Large strain and small-scale biaxial testing of sheet metals,” M.S. - Master of Science, Middle East Technical University, 2016.
METU IIS - Integrated Information Service open@metu.edu.tr