About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Aluminum Alloys: Development and Manufacturing
|
| Presentation Title |
Nano-level analysis on intergranular HE cracking path in relation to the interface between grain boundary precipitate and the matrix in an Al-Zn-Mg-Cu alloy |
| Author(s) |
Goroh Itoh, Ryota Nagai, Seiichiro Ii, Shigeru Kuramoto, Junya Kobayashi |
| On-Site Speaker (Planned) |
Goroh Itoh |
| Abstract Scope |
T6-tempered Al-Zn-Mg-Cu alloys are widely known to suffer from hydrogen embrittlement (HE), where cracks are prone to propagate along grain boundaries. At grain boundaries, precipitates slightly coarser than inside the grain are formed when the aging proceeds. The intergranular precipitates are reported to have an coherent or semi-coherent interface with one grain while incoherent with the other. In general, incoherent interface has higher interfacial energy than coherent interface, resulting in lower cohesive strength. However, recent simulation studies showed that hydrogen atoms tend to segregate at the coherent or semi-coherent interface promoting decohesion. In the present study, we have attempted to experimentally elucidate along which interface the HE cracks propagate. An Al-5.7%Zn-2.4%Mg-1.4%Cu alloy specimen was T6-tempered and then tensile-deformed to rupture under humid air at a slow strain rate to produce intergranular HE fracture surface, which then was characterized by means of high-resolution SEM, TEM and EBSD. |
| Proceedings Inclusion? |
Planned: Light Metals |
| Keywords |
Aluminum, Characterization, Mechanical Properties |