آنیل انحلالی، پیرسازی دومرحله‌ای و بررسی خسارت هیدروژنی آلیاژ آلومینیوم 7075

نویسندگان

دانشکده مهندسی مواد، دانشگاه صنعتی مالک اشتر اصفهان

چکیده

هدف از انجام این پژوهش، بررسی خسارت هیدروژنی آلیاژ آلومینیوم 7075، پس ‌‌از انجام آنیل انحلالی و پیرسازی دومرحله‌ای است. آنیل انحلالی در دما‌های 500 تا 575 درجه سانتی‌گراد به‌مدت 1 تا 20 ساعت انجام شد. مرحله اول پیرسازی دومرحله‌ای، در دماهای 180، 200 و 220 درجه سانتی‌گراد به‌مدت 30 دقیقه و مرحله دوم پیرسازی در دماهای 120 و 150 درجه سانتی‌گراد به‌مدت 10، 15 و 20 ساعت انجام گرفت. بررسی ساختاری به‌روش SEM و بررسی ترکیب شیمیایی رسوب­ها‌  به‌­روش EDS صورت گرفت. افت استحکام کششی در فرایند 6T پس از هیدروژن‌دهی 150 مگاپاسگال بود ولی در فرایند دومرحله‌ای این کاهش به 50 مگاپاسگال رسید. در مجموع، استحکام کششی پس از شارژ هیدروژن، در فرایند پیرسازی دومرحله‌ای نسبت به فرایند 6T به‌شدت افزایش یافت.

کلیدواژه‌ها


عنوان مقاله [English]

Evaluation of Hydrogen Damage in Aluminum 7075 Alloy after Dissolution Annealing and Two-stage Aging

نویسندگان [English]

  • S. Gholipour
  • S.R. Hosseini
  • R. Shoja Razavi
Faculty of Materials Engineering, Malek Ashtar University of Technology, Shahin Shahr, Iran
چکیده [English]

This study aims at investigation of the hydrogen damage after dissolution annealing and two-stage aging in aluminum 7075 alloy. Dissolution annealing was performed at 500 to 575 °C for duration of 1 to 20 hours. The first stage of two-stage aging was performed at 180, 200 and 220 °C for 30 minutes. The second stage was carried out at 120 and 150 °C for 10, 15 and 20 hours. Structural characteristics and chemical composition of precipitates was investigated using SEM and EDS methods, respectively. Reduction of the tensile strength in T6 process after hydrogenation reached to 150 MPa, although it decreased only, about 50 MPa in the two-stage process. Overall, tensile strength after hydrogen charging was significantly increased in the two-stage aging compared to the T6 process.

کلیدواژه‌ها [English]

  • Two-stage aging
  • Dissolution annealing
  • Aluminum 7075
  • Hydrogen damage
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