کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5451654 1398550 2017 20 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Microstructure and Mechanical Properties of 7005 Aluminum Alloy Components Formed by Thixoforming
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد شیمی مواد
پیش نمایش صفحه اول مقاله
Microstructure and Mechanical Properties of 7005 Aluminum Alloy Components Formed by Thixoforming
چکیده انگلیسی
In the present research, semisolid billet of 7005 aluminum alloy was fabricated by using recrystallization and partial remelting (RAP), then thixoformed at different isothermal temperatures, preheating temperatures and load routes. Mechanical properties and microstructure of the thixoformed product were investigated. The results showed that microstructure achieved by three-step induction heating warm extruded 7005 aluminum alloy consists of a uniform and spheroidal microstructure suitable for thixoforming. Preheating temperature of the die affected significantly the filling status of semisolid billet of 7005 aluminum alloy. Complete filling status with good surface quality was obtained at a preheating temperature of 365 °C. Thixoformed microstructures consisting of relatively spheroidal grains illustrate the dependence of filling process on the sliding and rotating of solid grains rather than plastic deformation of solid grains. A non-uniform distribution of liquid phase was found in the different regions of the thixoformed product due to the slower adjustable velocity of solid grains as compared with liquid phase. Increase of isothermal temperatures led to a slight decrease of mechanical properties of the thixoformed product due to coarsening of solid grains. The highest yield strength, ultimate tensile strength and elongation of thixoformed components with T6 heat treatment are 237 MPa, 361 MPa and 16.8%, respectively, which were achieved at the isothermal temperature of 605 °C. Load route has a significant effect on mechanical properties and microstructure of the thixoformed product. Defects, such as crack and microporosity occurred in the microstructure of the thixoformed product obtained under load route 2. It led to an obvious reduction of mechanical properties as compared with route 1. A better compatibility of deformation caused by more liquid fraction at the isothermal temperature of 612 °C is beneficial to reducing non-uniformity of liquid phase in the different regions of the thixoformed product.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Materials Science & Technology - Volume 33, Issue 4, April 2017, Pages 379-388
نویسندگان
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