Sự biến đổi vi cấu trúc và các tính chất cơ học của hợp kim Mg–6Zn–1.5Ca (wt%) qua quá trình ép nóng

Journal of Materials Research - Tập 33 - Trang 1003-1010 - 2020
Yuzhou Du1,2, Mingyi Zheng3, Bailing Jiang1,2
1School of Materials Science and Engineering, Xi’an University of Technology, Xi’an, People’s Republic of China
2Shaanxi Province Engineering Research Center for Magnesium Alloys, Xi’an University of Technology, Xi’an, People’s Republic of China
3School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, People’s Republic of China

Tóm tắt

Vi cấu trúc và tính chất kéo của hợp kim Mg–6Zn–1.5Ca (wt%) được khảo sát qua phương pháp tán xạ điện tử ngược, kính hiển vi điện tử quét và kính hiển vi điện tử truyền qua. Một vi cấu trúc hai chế độ đã được hình thành, thể hiện gần hạt tinh thể mới tái kết tinh động (DRXed) với độ kết cấu yếu và vùng biến dạng thô với độ kết cấu cơ bản mạnh và các tinh thể mịn hình thành. Hợp kim Mg–Zn–Ca sau khi ép có độ bền giới hạn lên đến 305 MPa và độ kéo dài đến khi gãy vừa phải là 8.6%. Hiện tượng kết tủa động đã được phát hiện trong vùng biến dạng, điều này đã kìm hãm quá trình tái kết tinh động. Độ mạnh của cấu trúc kết cấu trong vùng DRXed đã yếu đi so với vùng biến dạng, điều này liên quan đến sự nucleation ưa thích trong quá trình tái kết tinh động. Những hiệu ứng yếu đi của cấu trúc này đã dẫn đến sự cải thiện rõ rệt về độ dẻo dai cho hợp kim sau khi ủ.

Từ khóa

#hợp kim Mg–6Zn–1.5Ca #vi cấu trúc #tái kết tinh động #tính chất cơ học #ép nóng

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