نوع مقاله : مقاله پژوهشی
1 دانش آموخته کارشناسی ارشد، مهندسی مواد، دانشگاه صنعتی نوشیروانی بابل
2 دانشیار گروه مهندسی مواد دانشگاه صنعتی نوشیروانی بابل
عنوان مقاله [English]
< p >The eddy current non-destructive testing (ECT) is one of the electromagnetic methods that can be used to evaluate and control the metallurgical quality of industrial alloys. The rapid implementation and digital nature of the answers have led to its use in setting up automatic inspection and quality control lines . The purpose of this paper is to investigate the metallurgical quality control conditions of 7075 aluminum alloy sheets after aging heat treatment using the ECT method. For this purpose, the destructive tests of metallography, hardness and electrical conductivity were performed along with the eddy currents non-destructive testing and then their data were compared with each other. The sheet samples of this alloy were prepared in the form of a 1.2 mm thickness. The solution heat treatment was performed at 470 centigrade for 20 minutes and then artificial aging heat treatment was performed at different temperatures and times. Microstructural studies were performed by optical and scanning electron microscopes, standard conductivity (% ICAS) and Brinell hardness methods. Then, using a eddy current apparatus at 8 kHz, the electromagnetic responses of the samples were evaluated and compared. The results showed that to quality control and assurance of the aged products, the use of hardness index alone can not suffice. In addition, the metallographic method has executive limitations in production processes. It was found that the eddy current responses are affected by microstructural changes resulting from aging process. Using this method, different parts of 7075 aluminum alloy can be non-destructively separated from each other.