Development of High-strength Ternary and Quaternary Thorium-uranium Base Alloys PDF Download

Author: R. H. Cole
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 160

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Book Description
The addition of alloying elements to base alloys of Th containing 5 and 10 wt% U was investigated with regard to alloy structures and elevated- temperature mechanical properties. The alloys developed possess elevated temperature tensile and stress-rupture strengths of essentially twice those associated with binary Th-5 and 10 wt% U alloys at 60O to 800 deg C. The greater strength of these alloys should resuit in improved resistance to radiation induced swelling at high temperatures. Noticeable improvement in elevated-temperature mechanical properties resulted from the addition of 2 and 5 wt% Zr to the Th-5 and Th-10 wt% U base alloys. Zr was found to be the most effective additive in improving elevated-temperature mechanical properties, although significant improvement was noted with additions of Nb, Mo, C, Al, and Be. Both solidsolution strengthening and dispersion strengthening of the Th --U base alloys were encountered. It was found that a fine intragranular distribution of the secondary U phase improved the mechanical properties of the alloys studied. Structures with optimum properties were produced by careful control of the arc-melting procedure and by solution heat treating at 1350 deg C followed by aging at 850 deg C. Preliminary testing was performed to determine the elevatedtemperature mechanical properties of Th metal and of the Th --U base alloys. Irradiation specimens of the most promising alloys were prepared. These specimens were encapsulated and are ready for irradiation testing at 800 deg C and for subjection to burnups of 10,000, 20,000 and 30,000 Mwd/ ton. (auth).