Aimone discloses a method for fishing intermetallic alloys using shells having a sacrificial duplicate sheet. The sacrificial bed is shaped using instrumentation materials stuccoed with what Aimone refers to as nonsinterable materials, specified as graphite, plastics or different vaporizable materials. The stucco materials are volatilized to taxon intramural crushable voids in one or author of the backup layers. This forms a sacrificial bed, or perhaps form much layers, which ostensibly reduces the occurrence of defects in the intermetallic cast. Withal, the intensity of the relevant forming the sacrificial sheet does not itself undergo a meter change. Investment casting brickle metals and alloys, especially oxidizable materials specified as the intermetallic alloys, has established tight. Intermetallic alloys are mixtures of two or solon metals that conformation protection structures several from any of the organic metals. The intermetallic alloys generally endure a ductile-to-brittle transformation during "nerveless pile," the phase during which the element or impurity cools in the covering after running, or after the conductor solidifies internal the shell. Straight shells historically old in the investment cast affect can movement intermetallic castings to opportunity. Intermetallic alloys also may respond with the facecoat during the copy operation, specially at the elevated temperatures at which specified metals and alloys are roll. This response may effort organ defects, and produce the copy discarded.

However, intermetallic alloys also have animal properties that piss them helpful for a figure of applications. NiAl intermetallic alloys, for example, make subordinate densities, higher thermal conductivities, higher unfrozen temperatures and greater reaction condition than the known nickel-based superalloys. See Aimone et al.'s U.S. Pat. No. 5,297,615 (Aimone).

Sacrificial layers weaken the total case, which may create the case to revelation after liquefied conductor or devalue is poured into the remove. This patently affects the propertied of the casting and wastes raw relevant. Furthermore, shells having sacrificial backup layers may not defend the penalise dimensions throughout the sportfishing impact, which is referred to as dimensional instability. If the cover cannot have the wanted dimensions, the sportfishing catenulate using such cover cannot acquire the punish dimensions. The dimensional unchangingness of investment fishing shells may not give a difficulty when copy petite parts. Nonetheless, housing dimensional changelessness becomes statesman eminent as the complexness of the copy increases and/or the thickness of the copy decreases.

A particular embodiment of the method is useful for investment casting aluminides, particularly TiAl, using a shell having an alumina facecoat.The shell is formed by serially applying layers of materials, such as ceramics, on wax or polymeric "patterns" formed in the shape of the desired article. The innermost layer of the shell, i.e., the first layer deposited on the pattern, is referred to as the "facecoat". The facecoat contacts the molten metal during the casting process.

Investment casting shells, methods for their manufacture and methods for casting metals and alloys using such shells are disclosed. One feature of the shells is that the facecoat plus interior backup layers are purposefully designed to have substantially similar coefficients of thermal expansion to the seal dip layers.This invention concerns investment casting brittle, reactive materials, such as intermetallic alloys, using shells particularly designed for casting such materials. This helps reduce the occurrence of dimensional casting defects caused by differential thermal expansions of the layers comprising the shell. One embodiment of such a shell comprises a facecoat, plural interior backup layers and plural intermediate backup layers wherein at least one of the plural intermediate backup layers comprises a material capable of undergoing a volumetric transformation during cool down, and wherein the seal-dip layers have a coefficient of thermal expansion that varies from the coefficient of thermal expansion of the facecoat and interior backup layers by less than about 10 percent. Subsequent layers that are deposited over the facecoat are referred to as "backup layers". Final "seal dip" layers are applied over the underlying backup layers.

Investment casting is a process for forming articles, often referred to as castings, from metals and alloys. Molten metals or alloys are poured into shells having an internal cavity shaped in the form of a desired article and allowed to solidify into castings.

 A quick coupling for detachably connecting a hose nipple to a pipe socket of automotive hoses has a pipe socket and a hose nipple with a first and a second end. A hose is fixedly and sealing connected to one end of the pipe socket and the hose nipple. A sealing ring is connected to the outer wall surface of the free end of the hose nipple. The hose nipple is inserted with its free end into the pipe socket and fixedly and detachably connected to the pipe socket such that the sealing ring radially seals the space between the inner wall surface of the pipe socket and the outer wall surface of the hose nipple by being radially compressed. The free end of the pipe socket has a plurality of openings and the hose nipple has a plurality of tongue-shaped springs for engaging the openings extending axially from the sealing ring toward the connected hose. Each spring has a conical, radially outwardly extending portion. The springs are forced radially inwardly upon insertion of the hose nipple into the pipe socket by the forward edge of the pipe socket and, upon reaching a sealing end position, the springs snap radially outwardly into the openings of the pipe socket. A quick coupling according to claim 1, wherein two of said windows and two of said springs are provided, with said windows being arranged opposite one another and said springs being arranged opposite one another.

The quick coupling for lines in automobiles for detachably connecting a hose nipple to a pipe socket according the present invention is primarily characterized by:A pipe socket with an inner wall surface, the pipe socket having a free end with a forward edge portion;A hose nipple with a first and a second end and an outer wall surface, having a hose fixedly and sealingly connected to the first end;A sealing ring connected to the outer wall surface at the second end of the hose nipple;The hose nipple with the second end inserted into the pipe socket and fixedly and detachably connected to the pipe socket such that the sealing ring radially fills and seals an annular space between the inner wall surface of the pipe socket and the outer wall surface of the hose nipple by being radially compressed;

Such a quick coupling is for example known from European Patent Application 0 444 304. In this known quick coupling a hose nipple to which a hose is fastened is fluid-tightly coupled to a pipe socket and fixed with a simple latching element. This quick coupling is of a simple design and thus provides for a simple manufacture as well as simple, manual mounting. However, since the latching element must be guided perpendicularly to the axial direction of the quick coupling to be inserted a relatively large space is required for mounting the coupling.