Abstract: A joining method designed to minimize the temperature needed to obtain a high strength braze joint between a molybdenum alloy substrate and a graphite disk used in a rotating anode X-ray tube target used for computed tomography applications. The method consists of two separate brazing operations. The first brazing operation joins a thin molybdenum sheet to the graphite disk using a pure metal braze to form a plated graphite subassembly. The second brazing operation joins the plated graphite subassembly to the molybdenum alloy substrate using a highly specialized braze alloy having a melt temperature below the recrystallization temperature of said molybdenum alloy substrate and a remelt temperature after brazing above the recrystallization temperature of said molybdenum alloy substrate.

Abstract: A joining method designed to minimize the temperature needed to obtain a high strength braze joint between a molybdenum alloy substrate and a graphite disk used in a rotating anode X-ray tube target used for computed tomography applications. The method consists of two separate brazing operations. The first brazing operation joins a thin molybdenum sheet to the graphite disk using a pure metal braze to form a plated graphite subassembly. The second brazing operation joins the plated graphite subassembly to the molybdenum alloy substrate using a highly specialized braze alloy having a melt temperature below the recrystallization temperature of said molybdenum alloy substrate and a remelt temperature after brazing above the recrystallization temperature of said molybdenum alloy substrate.

Abstract: A joining method designed to minimize the temperature needed to obtain a high strength braze joint between a molybdenum alloy substrate and a graphite disk used in a rotating anode X-ray tube target used for computed tomography applications. The method consists of two separate brazing operations. The first brazing operation joins a thin molybdenum sheet to the graphite disk using a pure metal braze to form a plated graphite subassembly. The second brazing operation joins the plated graphite subassembly to the molybdenum alloy substrate using a highly specialized braze alloy having a melt temperature below the recrystallization temperature of said molybdenum alloy substrate and a remelt temperature after brazing above the recrystallization temperature of said molybdenum alloy substrate.

Abstract: A method is provided for enhancing heat transfer within an X-ray vacuum tube, from a hot component such as the rotating anode assembly to a cooler component such as the metal tube housing, by increasing surface emissivity of respective components. The method comprises the steps of fabricating each component from an alloy containing a specified minimum amount of chromium, and then implementing a first heating operation, wherein a fabricated component is heated in a dry hydrogen atmosphere for a first specified time period. Thereafter, a second heating operation is implemented, wherein the fabricated component is heated in a wet hydrogen atmosphere for a second specified time period. This procedure forms a refractory chromium oxide coating on the component that exhibits high absorption in the NIR region of the electromagnetic spectrum.

Abstract: A technique is disclosed for providing a solid state X-ray detector for a CT imaging system with an optical coupler having a substantially reduced coefficient of thermal expansivity (CTE). In accordance therewith, a prespecified amount of a ceramic scintillator material, in powdered form, is mixed with the resin component of an optical coupling material, such as transparent epoxy, which has resin and hardener components. Air bubbles are removed from the powdered scintillator-resin mixture, and a prespecified amount of the hardener component of the optical coupling material is combined therewith to provide a powdered scintillator-optical coupler composite. The CTE of the composite is substantially less than the CTE of epoxy only. A monolithic block or body of the ceramic scintillator material is placed in close, spaced-apart relationship with a photodiode device, and the gap therebetween is filled with the reduced CTE optical coupler composite to eliminate air spaces therefrom.