Small-angle neutron scattering study of the decomposition of Fe-28Cr-10. 5Co. [none]
Dynamic scaling of the decomposition of an Fe-28Cr-10.5Co alloy treated at 450/sup 0/, 500/sup 0/, and 550/sup 0/C after a water quench from 950/sup 0/C was investigated with small-angle neutron scattering. Scattering curves measured from the alloy treated at 500/sup 0/C and 550/sup 0/C for times up to 100 hours can be superimposed on a common curve using a k/sub m/-/sup 1/-scaling of the scattering vector length (k = 4..pi..sin(theta)/lambda) and k/sup 3//sub m/-scaling of the scattering intensity scale, where k/sub m/ is the scattering vector for maximum intensity for each scattering curve. At 450/sup 0/C, however, such dynamic scaling does not apply for treatment times between 32 and 192 hours. The 450/sup 0/C curve for 256 hours does scale to the common curve for treatments at 500/sup 0/C and 550/sup 0/C. The departure from scaling found at 450/sup 0/C is consistent with the absence of sharp interfaces and the persistence of localized clustering or critical scattering in the chromium-rich and iron-rich regions. An analysis of the shape of the scattering curves was made in terms of a cluster interference function. It was found that a Gaussian single cluster function is modulated by a cluster interference function given by (k/k*)/sup n/ exponent n is approximately 4 and k* is the limit in k beyond which the interference function is unity. This exponent is larger than that found in computer simulations and in experimental studies of spinodal systems.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6834318
- Report Number(s):
- CONF-8404141-3; ON: DE84011665
- Resource Relation:
- Conference: International topical conference on kinetics of aggregation and gelation, Atlanta, GA, USA, 2 Apr 1984
- Country of Publication:
- United States
- Language:
- English
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