21 Result(s)
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Article
S. L. Cockcroft
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Article
Porosity Prediction in A356 Wheel Casting
A FLUENT™-based thermal-fluid-compositional model has been developed and applied to a low-pressure, die-cast, A356 aluminum alloy wheel to explore the effects of macro-segregation of hydrogen and late-stage li...
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Article
Process Modeling of Low-Pressure Die Casting of Aluminum Alloy Automotive Wheels
Although on initial inspection, the aluminum alloy automotive wheel seems to be a relatively simple component to cast based on its shape, further insight reveals that this is not the case. Automotive wheels ar...
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Article
Modeling the Stress-Strain Behavior and Hot Tearing during Direct Chill Casting of an AZ31 Magnesium Billet
Quantitative knowledge of the thermal mechanical history experienced during direct chill (DC) casting aids the scientific understanding of the process especially in terms of defect formation such as hot tearin...
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Quantitative Assessment of Deformation-Induced Damage in a Semisolid Aluminum Alloy via X-ray Microtomography
Semisolid tensile testing combined with X-ray microtomography (XMT) was used to characterize the development of internal damage as a function of strain in an aluminum-magnesium alloy, AA5182. Novel techniques ...
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Effect of Sample Start Temperature during Transient Boiling Water Heat Transfer
The influence of the initial sample start temperature (400 °C to 1000 °C) on the boiling water heat-transfer behavior during quenching of AISI 316 stainless steel plates has been examined. The study involved i...
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Determination of Strain during Hot Tearing by Image Correlation
The evolution of strain and strain at the onset of localization resulting in a hot tear has been determined for alloys AA6111, AA3104, CA31218, and Al-0.5 wt pct Cu during solidification. A bar constrained at ...
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Article
Modeling of microporosity formation in A356 aluminum alloy casting
A numerical model for predicting microporosity formation in aluminum castings has been developed, which describes the redistribution of hydrogen between solid and liquid phases, the transport of hydrogen in li...
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Casting defects in low-pressure die-cast aluminum alloy wheels
Defects in automotive aluminum alloy casting continue to challenge metallurgists and production engineers as greater emphasis is placed on product quality and production cost. A range of casting-related defect...
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Development and validation of a thermal model of the direct chill casting of AZ31 magnesium billets
A mathematical model of the direct chill (DC) casting process for magnesium billets has been developed to predict the temperature in the billet, dummy block, and center pin using the commercial finite-element ...
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On the development of a three-dimensional transient thermal model to predict ingot cooling behavior during the start-up phase of the direct chill-casting process for an AA5182 aluminum alloy ingot
The control of the heat transfer during the start-up phase of the direct-chill (DC) casting process for aluminum sheet ingots is critical from the standpoint of defect formation. Process control is difficult b...
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X-ray-based measurement of composition during electron beam melting of AISI 316 stainless steel: Part I. Experimental setup and processing of spectra
An energy dispersive X-ray (EDX) detector mounted on a laboratory scale electron beam furnace (30 kW) was employed to assess the potential use of X-rays as a means of on-line liquid alloy composition monitorin...
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Article
X-ray-based measurement of composition during electron beam melting of AISI 316 stainless steel: Part II. Evaporative processes and simulation
An energy dispersive X-ray (EDX) detector mounted on a laboratory scale electron beam furnace (30 kW) was employed to assess the potential use of X-rays as a means of on-line composition monitoring during elec...
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Article
X-ray-based measurement of composition during electron beam melting of AISI 316 stainless steel: Part I. Experimental setup and processing of spectra
An energy dispersive X-ray (EDX) detector mounted on a laboratory scale electron beam furnace (30 kW) was employed to assess the potential use of X-rays as a means of on-line liquid alloy composition monitorin...
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Article
X-ray-based measurement of composition during electron beam melting of AISI 316 stainless steel: Part II. Evaporative processes and simulation
An energy dispersive X-ray (EDX) detector mounted on a laboratory scale electron beam furnace (30 kW) was employed to assess the potential use of X-rays as a means of on-line composition monitoring during elec...
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Article
Influence of surface morphology, water flow rate, and sample thermal history on the boiling-water heat transfer during direct-chill casting of commercial aluminum alloys
An experimental investigation has been conducted on as-cast samples from three commercially significant aluminum alloys (AA1050, AA3004, and AA5182) to quantify the influence of surface morphology, water flow ...
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Article
Freckle formation and freckle criterion in superalloy castings
The evaluation of a numerical criterion to provide quantitative insight on freckling conditions is critical to the successful manufacture of large superalloy castings. Of the criteria reported in the literatur...
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Article
A two-dimensional model for the description of the columnar-to-equiaxed transition in competing gray and white iron eutectics and its application to calender rolls
A two-dimensional (2-D) microstructural model has been developed for the description of the solidification of gray and white iron eutectics at the scale of a casting process. The model deals with the competiti...
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Article
Mathematical modeling of microstructural development in hypoeutectic cast iron
A mathematical heat-transfer/microstructural model has been developed to predict the evolution of proeutectic austenite, white iron eutectic, and gray iron eutectic during solidification of hypoeutectic cast i...
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Article
Heat-flow-based analysis of surface crack formation during the start-up of the direct chill casting process: Part II. experimental study of an AA5182 rolling ingot
The flow of heat during the start-up of the direct chill (DC) casting process has been studied with the aim of determining the factors that make this phase of the process prone to face crack generation. Measur...
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Heat-flow-based analysis of surface crack formation during the start-up of the direct chill casting process: Part I. development of the inverse heat-transfer model
A method for determining the temperature dependence of heat transfer in the direct chill (DC) water regime of the DC casting process has been developed. The technique uses as input the data acquired from one e...
