โครงสร้างจุลภาคของโลหะผสมอะลูมิเนียมความแข็งแรงสูงพิเศษ (AI-Zn-Mg-Cu) ภายหลังการแข็งตัวและภายหลังกระบวนการอบเป็นเนื้อเดียวที่ผ่านการหล่อด้วยกระบวนการ Direct Chill ภายใต้การกวนของแม่เหล็กไฟฟ้าความถี่ต่ำ
Solidified and homogenized microstructures of super high strength aluminium Al-Zn-Mg-Cu alloys produced by low frequency electromagnetic casting (LFEC) were studied in composition range of Zn; 6.0-10.0%, Mg; 1.0-2.5%, Cu; 1.0-2.3%. Many phases were found along grain boundaries after solidification,...
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Theses and Dissertations |
| Language: | Thai |
| Published: |
จุฬาลงกรณ์มหาวิทยาลัย
2008
|
| Subjects: | |
| Online Access: | https://digiverse.chula.ac.th/Info/item/dc:44377 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Institution: | Chulalongkorn University |
| Language: | Thai |
| Summary: | Solidified and homogenized microstructures of super high strength aluminium Al-Zn-Mg-Cu alloys produced by low frequency electromagnetic casting (LFEC) were studied in composition range of Zn; 6.0-10.0%, Mg; 1.0-2.5%, Cu; 1.0-2.3%. Many phases were found along grain boundaries after solidification, which were formed mostly by eutectic reaction. The amount of eutectic structures decreased with the reduction of alloying elements content, especially Mg, having more effect on the amount of eutectic structures than those of Zn and Cu. ƞ (MgZn₂) included with Cu is a major eutectic phase. Besides, the other secondary phases were discovered such as S (Al₂CuMg), Ɵ (Al₂Cu), Al₇Cu₂Fe, T (Mg₃₂(Al,Zn)₄₉), Mg2Si and Al₃Zr. These constituents changed with alloying elements content. Solidification sequence of Al-10.0Zn-2.5Mg-2.3Cu cast by LFEC was determined as follows; Al₃Zr, Al (α), Al₇Cu₂Fe, MgZn₂, S (Al₂CuMg), T (Mg₃₂(Al,Zn)₄₉) and Mg₂Si + Ɵ (Al₂Cu), respectively. The homogenized microstructure evolution at 460 ℃ was studied, the amount of eutectic structures were reduced with increasing homogenization time and the eutectic structures were less connected as the network. MgZn₂ is dissolved into the matrix aluminium phase during homogenization. However, Al₇Cu₂Fe และ S (Al₂CuMg) remained in homogenized alloys. |
|---|