Abstract: A method for estimating proper eutectic modification level in a liquid metal to minimize macro shrinkage porosity and gas bubbles during casting of aluminum automobile components, and a system and article for casting.

Abstract: A method for estimating proper eutectic modification level in a liquid metal to minimize macro shrinkage porosity and gas bubbles during casting of aluminum automobile components, and a system and article for casting.

Abstract: A method and system for optimizing a simulated casting of a light weight alloy component. The simulation includes passing component design data through various computational modules relating to casting designs, process modeling and optimization, material microstructure and defects and product performance. Variations in microstructure and defects across various very small size scales are extended to increasingly larger scales to permit structural performance calculations of the cast component to take such non-uniformities into consideration. At least some of the modules employ an expert system-based approach to achieve the optimized results. The results can be compared to end user needs to determine if redesign of the part geometry or manufacturing process is needed.

Abstract: Embodiments of a method for non-isothermally aging an aluminum alloy are provided. The method comprises heating an aluminum alloy at a first ramp-up rate to a maximum temperature below a precipitate solvus value, cooling the alloy at a first cooling rate sufficient to produce a maximum number of primary precipitates, cooling at a second cooling rate until a minimum temperature is reached wherein the growth rate of primary precipitates is equal to or substantially zero, and heating the alloy at a second ramp-up rate to a temperature sufficient to produce a maximum number of secondary precipitates.

Abstract: A method and system for optimizing a simulated casting of a light weight alloy component. The simulation includes passing component design data through various computational modules relating to casting designs, process modeling and optimization, material microstructure and defects and product performance. Variations in microstructure and defects across various very small size scales are extended to increasingly larger scales to permit structural performance calculations of the cast component to take such non-uniformities into consideration. At least some of the modules employ an expert system-based approach to achieve the optimized results. The results can be compared to end user needs to determine if redesign of the part geometry or manufacturing process is needed.

Abstract: A system and method for predicting fatigue life in metal alloys for very high cycle fatigue applications. The system and method are especially useful for cast metal alloys, such as cast aluminum alloys, where a fatigue endurance limit is either non-existent or hard to discern. Fatigue properties, such as fatigue strength in the very high cycle fatigue region, are based on a modified random fatigue limit model, where the very high cycle fatigue strength and infinite life fatigue strength are refined to take into consideration the sizes of the discontinuities and microstructure constituents since the fatigue life scatter depends upon the presence of discontinuities and microstructure constituents. The sizes of the discontinuities and microstructure constituents that can initiate fatigue cracks can be determined with extreme value statistics, then input to the modified random fatigue limit model.

Abstract: A casting design system (101) is provided which comprises (a) a database (115) which contains casting design data and rules, (b) a user interface (109), in communication with the database, which accepts as input a product design (103) that is to be cast by a casting process, and (c) an inference engine (111) which is adapted to generate casting designs (114) from the input product design by searching the database and retrieving data therefrom.

Abstract: A system and method for predicting fatigue life in metal alloys for very high cycle fatigue applications. The system and method are especially useful for cast metal alloys, such as cast aluminum alloys, where a fatigue endurance limit is either non-existent or hard to discern. Fatigue properties, such as fatigue strength in the very high cycle fatigue region, are based on a modified random fatigue limit model, where the very high cycle fatigue strength and infinite life fatigue strength are refined to take into consideration the sizes of the discontinuities and microstructure constituents since the fatigue life scatter depends upon the presence of discontinuities and microstructure constituents. The sizes of the discontinuities and microstructure constituents that can initiate fatigue cracks can be determined with extreme value statistics, then input to the modified random fatigue limit model.

Abstract: Methods and systems of predicting fatigue life in aluminum castings that combines extreme values of both casting flaws and microstructures with multiscale life models. The multiscale life models account for differing fatigue crack initiation based on the size scale of the defect and microstructure features, including provisions for generally millimeter scale casting flaws, generally micrometer scale second phase particles by cracking or debonding, or submicrometer scale dislocation interactions with precipitates which form persistent slip bands. In the presence of casting flaws, the fatigue initiation life is negligible and the total fatigue life is spent in propagation of a fatigue crack from such flaws. In the absence of casting flaws, however, the total fatigue life is spent in both crack initiation and propagation, except for the case where fatigue cracks initiate from large second phase particles in a coarse microstructure.

Abstract: Methods and systems of predicting fatigue life in aluminum castings that combines extreme values of both casting flaws and microstructures with multiscale life models. The multiscale life models account for differing fatigue crack initiation based on the size scale of the defect and microstructure features, including provisions for generally millimeter scale casting flaws, generally micrometer scale second phase particles by cracking or debonding, or submicrometer scale dislocation interactions with precipitates which form persistent slip bands. In the presence of casting flaws, the fatigue initiation life is negligible and the total fatigue life is spent in propagation of a fatigue crack from such flaws. In the absence of casting flaws, however, the total fatigue life is spent in both crack initiation and propagation, except for the case where fatigue cracks initiate from large second phase particles in a coarse microstructure.

Abstract: Embodiments of a method for non-isothermally aging an aluminum alloy are provided. The method comprises heating an aluminum alloy at a first ramp-up rate to a maximum temperature below a precipitate solvus value, cooling the alloy at a first cooling rate sufficient to produce a maximum number of primary precipitates, cooling at a second cooling rate until a minimum temperature is reached wherein the growth rate of primary precipitates is equal to or substantially zero, and heating the alloy at a second ramp-up rate to a temperature sufficient to produce a maximum number of secondary precipitates.

Abstract: A method of removing a core from a CMC component in which the core was used to form an internal cavity. According to one embodiment of the invention, the core is removed from a fully densified CMC component by heating the component and core to a temperature at which the core deteriorates but below a temperature at which the component would melt or otherwise be damaged. According to a second embodiment of this invention, the component is only partially densified, and then impregnated with a coating material that is resistant to a leaching compound capable of removing the core. The core can then be removed using the leaching compound without damage to the internal surfaces of the component defined by the core when the component was fabricated.

Abstract: A method of removing a core from a CMC component in which the core was used to form an internal cavity. According to one embodiment of the invention, the core is removed from a fully densified CMC component by heating the component and core to a temperature at which the core deteriorates but below a temperature at which the component would melt or otherwise be damaged. According to a second embodiment of this invention, the component is only partially densified, and then impregnated with a coating material that is resistant to a leaching compound capable of removing the core. The core can then be removed using the leaching compound without damage to the internal surfaces of the component defined by the core when the component was fabricated.

Abstract: A method of removing a core from a CMC component in which the core was used to form an internal cavity. According to one embodiment of the invention, the core is removed from a fully densified CMC component by heating the component and core to a temperature at which the core deteriorates but below a temperature at which the component would melt or otherwise be damaged. According to a second embodiment of this invention, the component is only partially densified, and then impregnated with a coating material that is resistant to a leaching compound capable of removing the core. The core can then be removed using the leaching compound without damage to the internal surfaces of the component defined by the core when the component was fabricated.