Microstructural investigation of controlled short circuiting gas metal arc welding deposited aluminium-lithium alloy

作者：Heard D W; Gauvin R; Brochu M^*

来源：Canadian Metallurgical Quarterly, 2014, 53(4): 416-422.

DOI：10.1179/1879139514Y.0000000146

• Aluminium alloys
• Welding
• Controlled short circuiting gas metal arc welding

Controlled short circuiting gas metal arc welding (CSC-GMAW) was investigated as a potential solid freeform fabrication (SFF) process for AA2199. The low heat input of the CSC-GMAW process resulted in a cooling rate on the order of 840-3500 degrees C s(-1) being realised during deposition. The solidification time was then calculated to range between 2-5 ms depending on the location within the weldment. The depositedmaterial displayed a fine (4.3 +/- 1 mu m) cellular structure, comparable to that previously reported for electron beam welding. Through comparison with the Kurz-Giovanola-Trivedi (KGT) model for microstructural development during solidification, the solidification front velocity (SFV) of the CSC-GMAW process was estimated to be similar to 2-4.5x10(-4) m s(-1). Chemical analysis revealed lateral segregation of copper to the cell walls. TOF-SIMS revealed a homogeneous lateral lithium distribution, however depth profiling displayed some extent of lithium enrichment at the surface of the deposited material.

• 出版日期2014-10