Sumitomo Chemical Company, Limited

The Texas A&m University System

Lacy Clark McDonald

Akihiko Takahashi

Karl T Hartwig

Hitoshi Yasuda

Hong Zou

The present invention concerns an aluminum alloy conductor of a cryostatic stabilizer for use at ultra low temperatures of 30.degree. K. or lower which is provided on and around a superconductor. The aluminum alloy conductor is made of 6 to 200 weight ppm of at least one element selected from the group of metallic and semimetallic effective elements consisting of B, Ca, Ce, Ga, Y, Yb and Th, and aluminum and inevitable impurities. The aluminum alloy conductor is obtained by adding at least one of these elements into a high purity aluminum whose purity is at least 99.98 wt. %. The aluminum alloy conductor has a 0.2% proof strength of not greater than 2.6 Kg/mm.sup.2.

High purity aluminum alloy conductor for use at ultra low temperatures

A method for manufacturing an aluminum alloy conductor for use at ultra low temperature which involves the steps of adding at least one of the metallic and semimetallic effective elements selected from the group consisting of B, Ca, Ce, Ga, Y, Yb and Th, in a total amount of 6 to 200 weight ppm, into a previously prepared molten high purity aluminum having a purity of not less than 99.98 wt % to thereby obtain a molten metal mixture; casting the molten metal mixture to thereby obtain a casting; subjecting the casting to extrusion working at 150.degree. C. to 350.degree. C. in an area reduction ratio of 1:10 to 1:150 whereby an extrusion worked product is formed; and annealing the extrusion worked product at a temperature of 250.degree. C. to 530.degree. C. for 3 to 120 minutes, whereby an aluminum alloy conductor for use at ultra low temperature is obtained.

Method of manufacturing a micro-alloy high purity aluminum conductor for

The aluminum conductor having increase of its electric resistivity kept small at ultra low temperature of 30.degree. K. or lower even after cyclic strain is given at ultra low temperature, by controlling the crystal structure of the high purity aluminum conductor with purity of 99.9-99.9999 wt % so as to consist of (i) a veritable single or a substantially single crystal consisting of a bundle of sub-grains which have their crystal axes in the same direction or in the directions within a couple of degrees of deviation as a whole which has a specific crystal axis of &lt;111&gt; or &lt;100&gt; or the crystal axes close thereto in the longitudinal direction of the aluminum conductor, or (ii) a polycrystal most of which grains have respective specific crystal axes of &lt;111&gt; and/or &lt;100&gt;, or the crystal axes close thereto with respect to each grain in the longitudinal direction of the aluminum conductor, and have specific grain size of 0.01 mm to 3.0 mm.

Method for making a high purity aluminum conductor used at ultra low

The aluminum conductor having increase of its electric resistivity kept small at ultra low temperature of 30.degree. K. or lower even after cyclic strain is given at ultra low temperature, by controlling the crystal structure of the high purity aluminum conductor with purity of 99.9-99.9999 wt %. The crystal structure consist of (i) a veritable single or a substantially single crystal consisting of a bundle of sub-grains which have their crystal axes in the same direction or in the directions within a couple of degrees of deviation as a whole which has a specific crystal axis of &lt;111&gt; or &lt;100&gt; or the crystal axes close thereto in the longitudinal direction of the aluminum conductor, or (ii) a polycrystal most of which grains have respective specific crystal axes of &lt;111&gt; and/or &lt;100&gt;, or the crystal axes close thereto with respect to each grain in the longitudinal direction of the aluminum conductor, and have specific grain size of 0.01 mm to 3.0 mm.

Growing community of inventors

Bryan, TX, United States of America

Lacy Clark McDonald