Constituents evolution of LFEC 7050 aluminum alloy during processing
(1. Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110004, China;
2. College of Software, Northeastern University, Shenyang 110004, China;
3. School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China)
2. College of Software, Northeastern University, Shenyang 110004, China;
3. School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China)
Abstract: The d 120 mm ingots of 7050 aluminum alloy were made by low frequency electromagnetic casting (LFEC) and conventional DC casting process, respectively. After homogenization treatment the ingots were extruded to rods and the solution and aging treatment were carried out for the rods. Constituents evolution during processing and effects of LFEC on constituents and remnant constituents were studied. The results show that 7050 aluminum alloy mainly contains Al-Zn-Mg-Cu type and Al-Cu-Fe type constituents. Al-Zn-Mg-Cu type constituents dissolve during homogenization, while Al-Cu-Fe type constituents could not dissolve. After homogenization treatment, the main remnant constituent is Al7Cu2Fe which crushes and orients along the extrusion direction after extrusion. Compared with DC process, by the process of LFEC, the constituents or remnant constituents are smaller in size and less in content. The LFEC process shows significant improvement in elongation by LFEC in both as-cast state and final state.
Key words: 7050 aluminum alloy; low frequency electromagnetic casting; microstructures; constituents