中國有色金屬學(xué)報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 18 No. 4 August 2008 |
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China;
3. Aerospace Research Institute of Materials and Processing Technology, Beijing 100076, China）
Abstract:7A52 Al alloy plate aged at 105 ℃ for 8 h and then at 130 ℃ for 24 h was welded by means of TIG using Al- 6.3Mg-0.35Sc-0.1Zr-0.1Cr solder wire. Mechanical properties and microstructures of welded joint were studied. There are two obviously soft areas in the welded joint, welding seam and over-aging zone. The mechanical properties of welded joint are that σb is 358 MPa, σ0.2 is 238 MPa and δ5 is 6.6%. 75.6% of welding coefficient can be achieved. The addition of scandium leads to very significant grain refinement in the fusion zone, which results in a reduction in solidification cracking tendency. The solidification cracking isn’t observed.
Key words: microalloying; Al alloy; welded joint; microstructure; mechanical properties
