PROPERTIES OF ENGINEERING MATERIALS FOR USE IN ROTATING MACHINERY AT CRYOGENIC TEMPERATURES

The properties of engineering materials which are useful to the designer of superconducting electrical machinery are discussed. Of all possible properties of a material, the ones most necessary to rotating machinery design are listed and defined. This is followed by a description of those organizations which both compile and store property data along with a description of those journals and books which contain property data. Seventy-six tables of numerical data with all the data referenced to their source are provided along with those reasonable conclusions which can be drawn from the data regarding how materials behave from room temperature to cryogenic temperatures. Comments are also made on those areas where further research is needed. This is followed by a bibliography of references for those who seek further detail. The data indicates that many materials have adequate cryogenic mechanical properties, particularly ductility, for use in superconducting electric machinery. Given a particular machine part with its design constraints, the designer must trade off the beneficial or detrimental effects of all the properties tabulated to find a material tailored to his needs.