Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 86 for “"castings"”.
-
Near-congruent solidification of castings
<p>A study on the microstructure development of as-cast Cu-Mn alloys based around the congruent minimum at 34.6 wt % Mn and 873 °C was performed. Initially, this was to evaluate the alloy as an alternative to wide freezing range Pb and Sn bronzes that are plagued with porosity. The shallow minimum …
-
Grain refinement in steel castings
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Metallurgy, 1960.
-
The prediction of bubble defects in castings
… and transport of gas bubbles in solidifying TiAl castings. The candidate has reviewed the literature, programmed in FORTRAN code, and validated a number of competing techniques for two phase flow relevant to the filling of moulds. He has developed a hybrid (Donor-acceptor/ Level Set) method, which …
-
Vibration assisted filling of thin section castings
… acceleration is approximately half that used in castings made without vibration. Two potential mechanisms were observed from the experimental result during the filling process in thin wall casting i] discontinuous propagation flow in vibration conditions; and ii] continuous propagation flow …
-
Heat flow in the solidification of castings
Thesis (Sc.D.) Massachusetts Institute of Technology. Dept. of Metallurgy, 1953
-
Predicting Stress Development in Gray Iron Foundry Castings
… predict stress development in gray iron foundry castings. Using a commercial finite element package with a user written element formulation, stresses resulting from thermal displacements in the cooling casting are computed while accounting for cast iron's radically different behavior in tension …
-
Modeling the microstructure development in gray iron castings
… and elimination of manufacturing defects in castings. Grain size and other microstructural features such as second phase morphology and distribution are the primary factors in determining the mechanical properties in cast metals. In this work, a representation of nucleation and growth …
-
A strategic analysis for a Chilean steel castings firm
Thesis: M.S., Massachusetts Institute of Technology, Sloan School of Management, 1992
-
The measles defect in CA-15 alloy steel castings
… on the surface condition of CA-15 alloy steel castings. This alloy often suffers from a peculiar defect known as measles, and an attempt was made to determine what reactions at the old-metal interface cause this defect. To this end, small cylindrical pins were rammed in sand molds and heated or …
-
Development of a generalized fatigue assessment approach for steel castings.
… fatigue assessment approach for steel castings for a range of internal casting quality details. In particular, this project examined the effect of quality details on the fatigue performance of steel castings using linear elastic fracture mechanics (LEFM) analysis. This is a research …
-
Reflectance map techniques for analyzing surface defects in metal castings
Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.
-
Mathematical modeling of microshrinkage formation during solidification of A356 alloy castings
… models that can predict micro shrinkage in castings were revised in detail. The main purpose of this study was to develop a comprehensive model which can predict micro-shrinkage pores that are forming during solidification of A356 castings. The model utilizes a stochastic approach and takes …
-
Understanding surface and sub-surface phenomena in nickel-based superalloy castings
… during the heat treatment. In the bespoke castings undertaken to further explore this phenomena clear evidence emerged of zircon particles, an integral constituent of the core, pinning the superalloy during the casting process. The result was a rough undulating surface with depressions …
-
Economic Analysis of 3D-Printed Ceramic Cores for GasTurbine Investment Castings
When manufacturing blades and vanes for gas turbine engines, internal cooling channels are formed by investment casting with sacrificial ceramic cores. The hot injection and pressing techniques traditionally used to manufacture ceramic cores have long lead times and high up-front costs, motivating …
-
A study of residual stresses in low alloy steel theta ring castings.
Residual stresses generated during the casting and heat treatment of a low alloy steel, BW2 have been studied using ta theta ring so that temperature differentials could be varied using different tie bar sizes. Residual stresses have been measured using centre hole drilling and tie bar sectioning …
-
Fundamental research regarding the ultrasonic stirring effects on the microstructure of A356 castings
Ultrasonic stirring treatment (UST) of molten metal has significant effects on the solidification microstructure of A356 alloy, which includes grain structure, distribution of inclusions, refinement of secondary phases, etc. The primary causes are due to ultrasonic cavitation, acoustic streaming …
-
Pre-Inoculation Effect of SiC in Production of Thin Wall Ductile Iron Castings
1 PDF file (66 pages)
-
Effect of pattern and coating properties on defect formation in aluminum lost foam castings
… of these defects in aluminum lost foam castings. Several statistically designed experiments were used to evaluate the effects of various gating designs, aluminum alloy compositions, foam pattern properties, and coating properties. Metal velocity measurements, along with the number, type, …
Page 1 of 5