Контрольная работа на тему Реферирование статьей по английскому языку

Содержание:

Study on Asymmetric Rolling Process Applied to Aluminum Alloy Sheets 2

Plastic Behavior and Microstructure Heterogeneity of an AA6063-T6 Aluminum Alloy Processed by Symmetric and Asymmetric Rolling 5

Flat Metal Rolling Simulation by Finite Volume Method 10

Effect of Grain Refinement and Dispersion of Particles and Reinforcements on Mechanical Properties of Metals and Metal Matrix Composites through High-Ratio Differential Speed Rolling 13

Influence of Intergranular Mechanical Interactions on Orientation Stabilities during Rolling of Pure Aluminum 18

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Study on Asymmetric Rolling Process Applied to Aluminum Alloy Sheets

Asymmetric rolling is a technique used to control both the texture and the grain refinement of metallic materials. The aim of asymmetric rolling is to apply a large shear strain uniformly through the thickness of the plate, by maintaining a high degree of friction between the sheet and the rolls. The objective of the present work is to investigate the effect of asymmetric rolling on an aluminum alloy used in the automotive industry. To this end, three parameters of the process were studied, namely the asymmetry factor (1, symmetric rolling (SR) and 1.36, asymmetric rolling (AR)), the thickness reduction per pass (10%, 15%, and 30%), and the rolling routes (asymmetric continuous (ARC) and asymmetric reverse (ARR)).

1) The structure of the problem. To study the asymmetric rolling process applied to aluminum alloy sheets, the authors resort to a number of techniques. After rolling, the material was tested by uniaxial tensile tests to measure its strength and formability. The results show similarity between all the rolling conditions, with a considerable increase in strength and a drastic decrease in formability. In addition, a prediction of forming limit diagram using an FLD code based on Marciniak–Kuczynski analysis was used to investigate the FLD evolution with rolling. The code was capable to capture the variation in formability during the rolling process, showing that it is a reliable numerical tool. A reasonable combination of high strength and acceptable formability was achieved by an adequate heat treatment applied after rolling.

Due to the pollution caused by vehicles, climate change requires action, which has led many experts to seek solutions. One such solution is the replacement of gasoline-powered vehicles with electric ones. However, an important aspect of the construction of all vehicles unrelated to the type of engine is the weight of the vehicle. Aluminum alloys are a good choice because they have a favorable strength-to-weight ratio. The use of aluminum in automotive components can reduce vehicle weight by up to 50%. However, the lower strength and formability of aluminum alloys compared to other materials such as high-strength steels limit their use in complex vehicle components.

2) Ways to solve the problem. The series based on Al-Mg-Si alloy is most used in automotive applications due to its good weld quality and good corrosion resistance, as well as reasonable strength and formability. The reduced formability of aluminum alloys due to symmetrical rolling and annealing is related to the development of cubic weave compositions. From this perspective, in order to reduce or eliminate the formation of cubic weave components, asymmetric rolling can be used to produce shear weave components, which are considered to have improved material formability characteristics. These components are obtained by shear deformation in the sheet thickness direction, as opposed to two opposite shear deformations produced in symmetrical rolling between the two surfaces and the mid-plane of the sheet. ASR is a rolling process that promotes asymmetry in the process.