THE ROLE OF CREEP IN THE GAS-PRESSURE-BONDING PROCESS
A theoretical method of determining the time, temperature, and pressure required for pressure bonding was proposed and then evaluated experimentally. The analysis considered only the mechanical deformation of the bonding surfaces induced by the external pressure. It was postulated that such deformations obey the power law for steady creep. The applicaiion of the law to the closure of thick-walled aluminum cylinders under gas pressure was investigated. The behavior was compared with ihat predicted from creep data obtained from short- time torsion creep tests. Only fair agreement was establtshed. The creep law was then applied to the calculation of the closure of voids at the interface between bonding surfaces. It was assumed that the voids exist as isolated spherical or cylindrical holes. The law failed to predict the total closure which occurred. Apparently, the creep law does not hold in the almost microscopic domain of the interfacial voids, although the disagreement may have been due to the oversimplification of the geometric representation. Resolution of the ambiguities probably will be attained only when sufficient experimental data to establish an empirical relationship of closure with bonding conditions are available. (auth) l8092 To develop fatigue-design information for the ORNL reactor programs, a study was made of the fatigue behavior of INOR-8, a nickel - molybodenum-chromium alloy for high-temperature service. The temperature and frequency dependence of fatigue properties of INOR-8 were determined by rotating- beam fatigue tests. Stress-lifetime data were obtained for temperatures of 1100, 1300, and 1500 deg F, and cyclic frequencies of 100, 600, and 3000 cpm. The fatigue strength of INOR-8 was found to decrease with increasing temperature. No appreciable frequency effect was found up to l300 deg F. At l500 deg F, there was a definite frequency effect, for the fatigue strengths of specimens tested at frequencies of 600 and 3000 cpm were equal, while the fatigue strength for tests at a frequency of l00 cpm was substantially lower. The studies indicated that there is a critical frequency associated with each temperature, above which frequency has no effect, but below which fatigue strength decreases with decreasing frequency. It was found that fatigue strength was higher for the finer grained material evaluated. ( auth)
- Research Organization:
- Battelle Memorial Inst., Columbus, OH (United States)
- DOE Contract Number:
- W-7405-ENG-92
- NSA Number:
- NSA-13-018091
- OSTI ID:
- 4240743
- Report Number(s):
- BMI-1351
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-59
- Country of Publication:
- United States
- Language:
- English
Similar Records
EFFECT OF CREEP-EXPOSURE ON MECHANICAL PROPERTIES OF RENE 41. PART II: STRUCTURAL STUDIES, SURFACE EFFECTS, AND RE-HEAT TREATMENT
MOLTEN-SALT REACTOR PROJECT QUARTERLY PROGRESS REPORT FOR PERIOD ENDING JANUARY 31, 1959