Synergistic enhancement of microstructure and properties in 304/TC4 cold metal transfer joints via laser pre-melting of FeCoNiCr medium-entropy alloys
To address the challenges of metal material repair and joining in the extreme environments specific to aerospace applications, this study conducted cold metal transfer welding of TC4 titanium alloy and 304 stainless steel by laser pre-melting FeCoNiCr medium-entropy alloy (MEA) onto TC4 surfaces. Th...
Saved in:
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-07-01
|
| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785425016187 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | To address the challenges of metal material repair and joining in the extreme environments specific to aerospace applications, this study conducted cold metal transfer welding of TC4 titanium alloy and 304 stainless steel by laser pre-melting FeCoNiCr medium-entropy alloy (MEA) onto TC4 surfaces. The microstructure and mechanical properties of the welded joints were comprehensively analyzed using optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), nanoindentation, electron backscatter diffraction (EBSD), transmission electron microscopy, and tensile testing. The research results demonstrated that the joint phase transition from Fe2Ti intermetallic compounds (IMCs) to FeNi3/Fe4Cr multi-phase structures was identified through microstructural morphology observations and diffraction pattern analysis using SEM and transmission electron microscopy (TEM), while the competitive mechanisms between MEA constituent atoms and base metal atoms were elucidated through molecular dynamics simulations. EBSD analysis revealed that the reduction in Kernel Average Misorientation (KAM) values was accompanied by diminished lattice distortion and localized strain, while the presence of special grain boundaries (Σ3 boundaries) was confirmed. Comparative fracture analysis of two experimental groups demonstrated a transition from brittle to mixed fracture modes, with the welded joint achieving a maximum tensile strength of 88.3 MPa, representing a 35.2 % enhancement compared to the non-additive baseline. These findings underscored the technological potential of FeCoNiCr MEA in advanced welding applications. |
|---|---|
| ISSN: | 2238-7854 |