Accession Number:

AD0608671

Title:

STRESS-DEPENDENT INTERACTIONS BETWEEN CESIUM AND OTHER MATERIALS.

Descriptive Note:

Final rept. for 1 Nov 63-31 Oct 64,

Corporate Author:

IIT RESEARCH INST CHICAGO ILL

Personal Author(s):

Report Date:

1964-11-18

Pagination or Media Count:

75.0

Abstract:

A summary of the effects of the presence of cesium liquid or vapor upon the mechanical behavior of materials germane to thermionic diode construction is presented. These studies include static and dynamic bend behavior, tensile behavior at several strain rates, fatigue behavior, and stress stability. The effects studied and reported herein are reversible in the sense that if the cesium is removed the effect disappears. This type of interaction is known as liquid or vapor metal embrittlement. None of the metallic materials was catastrophically embrittled. Reductions in ductility were observed, and, in one case 18-8 stainless steel a reduction in yield stress was evident. Both tungsten and Kovar showed improved ductility in the presence of cesium. The alumina ceramic materials examined were found to be influenced by cesium unless a glassy grain boundary phase was present. Unfortunately these latter materials are known to suffer a diffusiondependent deterioration in cesium. The reduction in strength of the higher all crystalline alumina is, small. The yttria ceramics examined were seriously weakened by molten cesium and must therefore be evaluated with care for these applications. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE