Method of evaluation and identification for the design of effective inoculation agents
First Claim
1. A method of evaluating or identifying effective and ineffective inoculation agents in a bulk metal or metal alloy, the method comprising the steps of:
- (a) heating the bulk metal or metal alloy to a molten state;
(b) emulsifying the bulk metal or metal alloy containing the inoculation agents in a molten state in a carrier fluid to produce micron-sized droplets;
(c) cooling the metal and the carrier fluid to cause solidification of the bulk metal or metal alloy, and simultaneously recording the thermal signals produced by the metal droplets;
(d) re-heating the bulk metal or metal alloy to a molten state;
(e) emulsifying the bulk metal or metal alloy containing the inoculation agents a second time in a molten state in the carrier fluid to produce micron-sized droplets;
(f) quenching the metal droplets just below the initial nucleation onset temperature that is derived from the recordation of the thermal signals in step (c) to preserve the microstructure at the onset of the highest nucleation reaction temperature;
(g) examining the microstructures of the droplets and segregating the effective and ineffective inoculant particle based upon the microstructures associated with effective nucleation; and
(h) identifying specific active and inactive inoculant agents in the droplets.
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Accused Products
Abstract
The Droplet Emulsion Technique is used to produce droplets of bulk metal or metal alloys containing inoculant particles. Heterogeneous nucleation responses are then separated and identified with variances in inoculant chemistry, size, morphology, and surface conditions in the different droplets. Differential Thermal Analysis (DTA) is used to detect and to correlate thermal signals generated from as little as 50 droplets 75-100 μm in size, allowing the separation of signals generated by a minor fraction of the total droplet population. Quenching treatments are used on the samples during thermal analysis to retain the original solidification microstructures produced from effective inoculation. Differences between droplet solidification microstructures preserved from the quenching treatments allow for visual identification of effective and ineffective inoculant particles. The factors controlling effective inoculation of solid include the chemistry, morphology, crystal structure, and surface conditions of inoculant particles which are identified by using analytical x-ray and electron microbeam techniques.
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Citations
20 Claims
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1. A method of evaluating or identifying effective and ineffective inoculation agents in a bulk metal or metal alloy, the method comprising the steps of:
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(a) heating the bulk metal or metal alloy to a molten state; (b) emulsifying the bulk metal or metal alloy containing the inoculation agents in a molten state in a carrier fluid to produce micron-sized droplets; (c) cooling the metal and the carrier fluid to cause solidification of the bulk metal or metal alloy, and simultaneously recording the thermal signals produced by the metal droplets; (d) re-heating the bulk metal or metal alloy to a molten state; (e) emulsifying the bulk metal or metal alloy containing the inoculation agents a second time in a molten state in the carrier fluid to produce micron-sized droplets; (f) quenching the metal droplets just below the initial nucleation onset temperature that is derived from the recordation of the thermal signals in step (c) to preserve the microstructure at the onset of the highest nucleation reaction temperature; (g) examining the microstructures of the droplets and segregating the effective and ineffective inoculant particle based upon the microstructures associated with effective nucleation; and (h) identifying specific active and inactive inoculant agents in the droplets. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of evaluating or identifying effective and ineffective inoculant agents in a bulk metal or metal alloy, the method comprising the steps of:
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(a) heating the bulk metal or metal alloy to a molten state; (b) emulsifying the bulk metal or metal alloy containing the inoculation agents in a molten state in a carrier fluid to produce micron-sized droplets; (c) quenching the metal droplets to cause solidification of the metal in the droplets and preserve the microstructure thereof; and (d) detecting thermal signals and correlating endothermic and exothermic events to specific inoculation agents within a fraction of the total droplet population. - View Dependent Claims (8, 9, 10, 11)
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12. A method of evaluating or identifying effective and ineffective inoculation agents in a bulk metal or metal alloy, the method comprising the steps of:
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(a) heating the bulk metal or metal alloy to a molten state; (b) emulsifying the bulk metal or metal alloy containing the inoculation agents in a molten state in a carrier fluid to produce micron-sized droplets; (c) quenching the metal droplets to cause solidification of the metal in the droplets and preserve the microstructure thereof; and (d) examining the microstructures of the droplets to identify the effective and ineffective inoculant particles based upon the microstructures associated with effective nucleation. - View Dependent Claims (13, 14, 15, 16)
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17. A method of evaluating inoculation agents in a bulk metal or metal alloy, the method comprising the steps of:
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(a) heating the bulk metal or metal alloy to a molten state; (b) emulsifying the bulk metal or metal alloy containing the inoculation agents in a molten state in a carrier fluid to produce micron-sized droplets; (c) quenching the metal droplets to cause solidification of the metal in the droplets and preserve the microstructure thereof; (d) detecting thermal signals and correlating endothermic and exothermic events to specific inoculation agents within a fraction of the total droplet population; and (e) examining the microstructures of the droplets to identify the effective and ineffective inoculant particles.
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18. A method of evaluating inoculation agents in a bulk metal or metal alloy, the method comprising the steps of:
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(a) processing bulk metals or alloys which contain inoculant particles into droplets containing the incorporated inoculant particles by the droplet emulsion technique; (b) performing differential thermal analysis on the droplet samples containing inoculant particles to establish nucleation temperatures for effective inoculant particles; (c) heating the droplet samples above the melting temperature of the metal in the droplets and then quenching the droplet samples upon the onset of a nucleation temperature previously determined; (d) after the step of quenching, cross-sectioning the droplet samples and examining the droplet microstructures to identify the effective and ineffective inoculant particles in these samples. - View Dependent Claims (19, 20)
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Specification