About this Abstract |
Meeting |
2021 AWS Professional Program
|
Symposium
|
2021 AWS Professional Program
|
Presentation Title |
Influence of Focus and Deflection when Comparing Electron Beam Welds to Laser Welds in 304 Stainless Steel and Ti-6Al-4V |
Author(s) |
Joris Hochanadel, Tate Patterson, John Lippold, Boyd Panton, David Tung, Matthew Johnson |
On-Site Speaker (Planned) |
Joris Hochanadel |
Abstract Scope |
To reduce costs associated with weld development, it is desirable to produce similar welds with two different types of high energy density welding machines. A deeper insight into the laser and electron beam processes is needed to achieve this goal. In this study, partial penetration bead-on-plate welds were made on 304 stainless steel, 304L stainless steel, and Ti-6Al-4V using both high power fiber laser and electron beam processes, focusing on the weld geometries and microstructures. The main variables of interest were power and travel speed. These parameters were adjusted independently, keeping other parameters constant. Beam measurements were performed for both processes in order to produce and maintain similar conditions. Welds were made at sharp focus for the laser welds and either a sharp, deflected or defocused condition for the electron beam welds. The deflection pattern used for the electron beam welds was made to mimic the top-hat distribution of the laser.
Optical microscopy was used to measure weld geometries for the estimation of melting efficiencies. The melting efficiency of the stainless steel welds was similar for both the laser and the electron beam processes, regardless of the focus condition or power distribution. A reduction in melting efficiency was observed in the laser welds of titanium compared to either condition of the electron beam welds. This was attributed to the effect of vaporization on the beam-material interaction and material properties such as reflectivity or elemental vapor pressures. The microstructure of the stainless steel welds was consistent with prior literature. Limited metallographic analysis was conducted for the Ti-6Al-4V welds, but there was some evidence of a large amount of α’-martensite which transformed from large prior beta grains. |
Proceedings Inclusion? |
Definite: Other |