Low cycle thermal fatigue testing of beryllium grades for ITER plasma facing components
- Sandia National Labs., Livermore, CA (United States)
- Brush Wellman, Inc., Cleveland, OH (United States)
- Efremov Institute, (Russia)
- Russian Institute of Inorganic Materials (Russia)
A novel technique has been used to test the relative low cycle thermal fatigue resistance of different grades of US and Russian beryllium, which is proposed as plasma facing armor for fusion reactor first wall, limiter, and divertor components. The 30 kW electron beam test system at Sandia National Laboratories was used to sweep the beam spot along one direction at 1 Hz. This produces a localized temperature ``spike`` of 750{degree}C for each pass of the beam. Large thermal stresses in excess of the yield strength are generated due to very high spot heat flux, 250 MW/m{sup 2}. Cyclic plastic strains on the order of 0.6% produced visible cracking on the heated surface in less than 3000 cycles. An in-vacuo fiber optic borescope was used to visually inspect the beryllium surfaces for crack initiation. Grades of US beryllium tested included: S-65C, S- 65H, S-200F, S-200F-H, SR-200, I-400, extruded high purity, HIP`d spherical powder, porous beryllium (94% and 98% dense), Be/30% BeO, Be/60% BeO, and TiBe{sub 12}. Russian grades included: TGP-56, TShGT, DShG-200, and TShG-56. Both the number of cycles to crack initiation, and the depth of crack propagation, were measured. The most fatigue resistant grades were S-65C, DShG-200, TShGT, and TShG-56. Rolled sheet Be (SR-200) showed excellent crack propagation resistance in the plane of rolling, despite early formation of delamination cracks. Only one sample showed no evidence of surface melting, Extruded (T). Metallographic and chemical analyses are provided. Good agreement was found between the measured depth of cracks and a 2-D elastic-plastic finite element stress analysis.
- Research Organization:
- Sandia National Lab. (SNL-CA), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 206944
- Report Number(s):
- SAND-96-0337C; CONF-9509218-4; ON: DE96007430; TRN: 96:009264
- Resource Relation:
- Conference: 2. International Energy Agency (IEA) workshop on beryllium technology for fusion, Jackson, WY (United States), 6-8 Sep 1995; Other Information: PBD: [1996]
- Country of Publication:
- United States
- Language:
- English
Similar Records
The neutron irradiation effect on the mechanical properties and structure of beryllium
The analysis of beryllium-copper diffusion joint after HHF test