Abstract: A fuel element includes a plurality of coolant channels formed therein. Each of the coolant channels rotate around a longitudinal axis of the fuel element such that a lateral position of a respective coolant channel changes at different longitudinal levels along the longitudinal axis. In one example, the respective coolant channel substantially helically winds around the longitudinal axis. In another example, the changing lateral position of the respective coolant channel forms at least one twist along the longitudinal axis configured to smear a thermal profile of the fuel element to balance power distribution within the fuel element. For example, the at least one twist is configured to spiral a flow of a coolant or a propellant through the fuel element to temperature balance hot and cold spots in a nuclear reactor core. A fabrication method for the fuel element can include additive manufacturing.

Abstract: A method for the manufacture of fiber-reinforced three-dimensional objects using a refractory matrix material is described. The method includes the additive manufacturing of a green body from a powder-based refractory matrix material, followed by optional partial strengthening, followed by continuous fiber incorporation and reinforcement, followed by full densification via chemical vapor infiltration (CVI). The refractory matrix material can be a refractory ceramic or a refractory metal. The refractory matrix material is deposited according to a binder-jet printing process to produce a green body. The next strengthening step delivers a part ideal for handling. The part is then reinforced with continuous fiber via winding, braiding, or other method of attaching continuous fiber to the part. The composite part then undergoes a CVI step to achieve maximum density and a hermetic seal on all surfaces. Accordingly, complex refractory objects with improved mechanical integrity and toughness can be produced.

Abstract: A method for increasing tensile strength of a cold workable alpha-beta titanium alloy comprises solution heat treating a cold workable alpha-beta titanium alloy in a temperature range of T??106° C. to T??72.2° C. for 15 minutes to 2 hours; cooling the alpha-beta titanium alloy at a cooling rate of at least 3000° C./minute; cold working the alpha-beta titanium alloy to impart an effective strain in the range of 5 percent to 35 percent in the alloy; and aging the alpha-beta titanium alloy in a temperature range of T??669° C. to T??517° C. for 1 to 8 hours. Fastener stock and fasteners including solution treated, quenched, cold worked, and aged alpha-beta titanium alloys are also disclosed.

Abstract: A method for increasing tensile strength of a cold workable alpha-beta titanium alloy comprises solution heat treating a cold workable alpha-beta titanium alloy in a temperature range of T?-106° C. to T?-72.2° C. for 15 minutes to 2 hours; cooling the alpha-beta titanium alloy at a cooling rate of at least 3000° C./minute; cold working the alpha-beta titanium alloy to impart an effective strain in the range of 5 percent to 35 percent in the alloy; and aging the alpha-beta titanium alloy in a temperature range of T?-669° C. to T?-517° C. for 1 to 8 hours. Fastener stock and fasteners including solution treated, quenched, cold worked, and aged alpha-beta titanium alloys are also disclosed.

Abstract: A method for increasing tensile strength of a cold workable alpha-beta titanium alloy comprises solution heat treating a cold workable alpha-beta titanium alloy in a temperature range of T?-106° C. to T?-72.2° C. for 15 minutes to 2 hours; cooling the alpha-beta titanium alloy at a cooling rate of at least 3000° C./minute; cold working the alpha-beta titanium alloy to impart an effective strain in the range of 5 percent to 35 percent in the alloy; and aging the alpha-beta titanium alloy in a temperature range of T?-669° C. to T?-517° C. for 1 to 8 hours. Fastener stock and fasteners including solution treated, quenched, cold worked, and aged alpha-beta titanium alloys are also disclosed.