| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Ultrafine-grained and Heterostructured Materials (UFGH XI)
|
| Presentation Title |
On the Fracture Toughness of Gradient Pure Nickel |
| Author(s) |
Qin Yu, Ruqing Cao, Jie Pan, Yan Lin, Andrew Sweet, Yi Li, Robert Ritchie |
| On-Site Speaker (Planned) |
Qin Yu |
| Abstract Scope |
Favorable combinations of strength and ductility can be achieved in gradient metallic materials. However, this does not necessarily guarantee that the fracture resistance will be similarly superior. We describe here a fracture-mechanics-based study to evaluate the fracture toughness of gradient structured (GS) nickel. Specifically, cracks are grown in grain-size gradient ranging from the coarse grains to nano-grains (CG→NG) and vice versa (NG→CG), with the measured crack-resistance R-curves, compared to corresponding behavior in uniform nano-grained (NG) and coarse-grained (CG) materials. The gradient structures display an improved combination of high strength and toughness compared to uniform grain-sized materials. The crack-initiation toughness is far higher for cracks grown in the direction of the CG→NG gradient than vice versa; a result which we ascribe primarily to excessive crack-tip blunting in the coarse-grained microstructure. Both gradient structures, however, exhibit marked rising R-curve behavior with exceptional crack-growth toughnesses exceeding 200 MPa.m½. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume; Planned: Supplemental Proceedings volume |