摘要:
A method for reducing the loss of magnesium during the sintering of aluminum oxide articles, such as ceramic discharge vessels for lighting applications. Magnesium oxide is added to aluminum oxide articles to control grain growth during sintering, but the sintering causes magnesium loss from the article. In order to address this problem, one or more aluminum oxide articles that are enriched in magnesium oxide are added to the sintering furnace to stem the loss of magnesium oxide in the remaining articles. The enriched aluminum oxide article is made by soaking a porous aluminum oxide article in an aqueous solution of magnesium nitrate and heating the porous article to convert the magnesium nitrate to magnesium oxide. The enriched articles may then be added in one or several locations to the sintering furnace, where the magnesium from the enriched articles is released to suppress the magnesium loss.
摘要:
A ceramic discharge vessel in a green state prior to assembly includes a first discharge vessel part in a green state, a second discharge vessel part in a green state, wherein the first and second discharge vessel parts form a discharge vessel when joined together, and a first capillary attached to the first discharge vessel part and a second capillary attached to one of the first and second discharge vessel parts. To facilitate joining the first and second discharge vessel parts, a first removable handle is temporarily attached to the first discharge vessel part for maneuvering the first discharge vessel part, and a second removable handle is temporarily attached to the second discharge vessel part for maneuvering the second discharge vessel part.
摘要:
A ceramic discharge vessel for a lamp includes a hollow body, two capillaries that extend from a same side of the body, and a strengthening web between and joining the two capillaries to each other.
摘要:
An incandescent lamp that emits infrared light and a method of making the lamp includes a filament assembly inside a polycrystalline aluminum oxide (PCA) envelope, where the filament assembly preferably has a coiled tungsten filament, solid metal ends of tungsten or molybdenum attached to the coiled tungsten filament, and leads at distal ends of the solid metal ends. End caps are attached to ends of the envelope and have openings through which a respective one of the leads extends, where the leads are each made of an electrically conductive material having a coefficient of thermal expansion compatible with the end caps, such as niobium. The leads are attached to the end caps with glass-ceramic sealing frits. The end caps and sealing frits seal a suitable gas inside the envelope.
摘要:
A method of molding a ceramic vessel includes compressing a water-soluble powder, suspending the compressed powder shape in a mold, injecting a ceramic molding mixture into the mold, and dissolving the compressed powder by flushing the vessel with water. A core for making an arc discharge vessel that has a discharge chamber and two capillaries includes a molded core of the water-soluble powder having a shape of the discharge chamber, and preferably two capillary-forming pins extending from the molded core. An apparatus for removing the molded core that includes a water reservoir that preferably flushes water through the vessel and dissolves molded core.
摘要:
A ceramic discharge vessel for a high-intensity discharge lamp includes a hollow body and two capillaries attached to the body. The capillaries have respective electrodes therein, where portions of the electrodes inside the body are spaced from each other and have longitudinal axes that are not coplanar. That is, in contrast to the prior art where the longitudinal axes are coplanar, the capillaries herein are moved (in effect, rotated) to positions in which a first plane defined by a longitudinal axis of one capillary and a first point where a second capillary is attached to the body is intersected by a longitudinal axis of the second capillary only at the first point.
摘要:
A method of manufacturing a ceramic discharge vessel for a lamp application is described. The method uses a low viscosity suspension of ceramic powder in a liquid resin. The discharge vessel is formed layer by layer using a stereolithography system. Preferably, the layers are formed by locally exposing the ceramic-resin mixture to a UV light source that solidifies and cures the resin only in the areas which correspond to the particular cross-sectional profile of the discharge vessel for a respective layer.