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The Study of Anisotropic Behaviors of Rods and Bars of 7A04 Aluminium Alloy

Author: SunQiang
Tutor: ZhangZhiMin
School: University of North
Course: Materials Processing Engineering
Keywords: 7A04 aluminum alloy deformation temperature rate of deformation anisotropic behaviors
CLC: TG146.21
Type: Master's thesis
Year: 2011
Downloads: 105
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Abstract

Ultrahigh strength aluminum alloy has lots of very good properties, such as light mass, high specific strength, good toughness, excellent hot workability and available heat-treatment. It plays a major role in the field of transportation, aviation and aerospace, energy saving and consumption reduction. Some strength of fibrous grain and texture are produced in the process of production and machining. Anisotropy which is caused by fibrous grain and texture has serious influence on plastic deformation. How to control their harmful effects and use their advantages is a major subject.In this work,the laws of microstructure and property evolution of 7A04 alloy on the different deformation temperature and strain rate have been studied using the analysis method of room temperature tensile test, OM observation, high-temerature compressive experiment and X-ray diffraction. The purpose is to provide references for stipulating the hot machining process, prediction and conformity of microstructure and property.The research result of deformation temperature shows that when deformation begin（ before the peak of true stress） , the true stress of high temperature deformation increases with the increase of true strain; The ture stress decrease lightly and gradually turn to be stable after the peak of true stress. 7A04 alloy is sensitive to temperature. When strain rate is fixed, the true stress and steady flow of strain decrease conspicuously with the increase of the temperature. The observation of metallography shows that with the temperature increasing grain grow significantly.The research result of strain rate shows that the strain rate sensitivity of 7A04 alloy is low in the direction of 0°and 90°when temperature is 320℃in the compressive load; the strain rate sensitivity of 7A04 alloy is high when temperature is 400℃and 480℃in the compressive load The observation of metallography show-s that w-hen temperature is fixed，the size of grain has no obvious change between low and high strain rateThe research result of anisotropy show-that on the condition of the normal temperaturetensile and low temperature（T=320。C）and strain rate(ε=0．1s^-1)，the mechanicalproperties of 7A04 aluminum alloy make a great difference in the direction of 0。，45。and90。With the temperature increasing，the mechanical properties of 7A04 aluminum alloytend to be isotropicTexture measurement shows that alloy contain copper texture and brass texture Intensityof them is respectively six and eight grades And the alloy contains a spot of cube textureand goss texture Intensity ofthem is all three grades

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CLC: > Industrial Technology > Metallurgy and Metal Craft > Metallurgy and Heat Treatment > Metallic materials > Non - ferrous metals and their alloys > Light non-ferrous metals and their alloys > Aluminum
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