About this Abstract |
Meeting |
Superalloys 2024
|
Symposium
|
Superalloys 2024
|
Presentation Title |
Interfacial Strength Evaluation Between Sulfur-segregated Al2O3 and Ni-Al Single Crystal Alloy Using Nanoindentation |
Author(s) |
Chihiro Tabata, Toshio Osada, Takahito Ohmura, Tadaharu Yokokawa, Kyoko Kawagishi, Shinsuke Suzuki |
On-Site Speaker (Planned) |
Chihiro Tabata |
Abstract Scope |
Ni-base superalloys have excellent oxidation resistance, but impurity S drastically decreases their properties. This is due to the segregation of S to the oxide/substrate interface, but direct and quantitative measurements of the interfacial strength in relation to the S segregation level have not been widely conducted. The objective of this research is to quantitatively analyze the interfacial strength between the Al2O3 layer and Ni-base substrate interfacial strength, depending on the S segregation level, using nanoindentation. Ni-9.8 wt.% Al alloys were prepared by melting the material using either an Al2O3 crucible (high Sinterfacealloy) or a CaO crucible (low Sinterfacealloy). Nanoindentation tests using a 60 degree pyramidal diamond indenter were conducted, and the cross-sections of both specimens exposed the (100) plane. Indentation near the interface formed cracks at the boundary between the two layers, which can be observed as pop-ins in the load-depth curves. The amount of load at the initial pop-in most likely represents the interfacial strength between the Al2O3 layer and Ni-base substrate. A Weibull analysis of results showed that suppression of the S segregation level increased the critical â scale parameter for crack formation by 650 ěN. This suggests that we were able to successfully compare the effect of S segregation on the interfacial strength between the Al2O3 layer and the Ni-base substrate quantitatively |
Proceedings Inclusion? |
Definite: At-meeting proceedings |