Date of Award

2015

Degree Type

Thesis

Degree Name

Ph.D.

Department

Mechanical, Automotive, and Materials Engineering

First Advisor

Andrzej Sobiesiak

Second Advisor

Jerry Sokolowski

Keywords

Aluminum-Silicon Alloys, Casting, Heat Treatment, Nano Silicon Particles, Squeeze casting

Rights

CC BY-NC-ND 4.0

Abstract

The research presented in this PhD dissertation renders a novel nano and ultra-fine structured cast industrial grade hypereutectic Al-Si-Cu engineering material and processing technologies capable of maximizing its functional characteristics. This development will allow for further engineering of exceptionally lightweight and near net-shape components for aerospace and transportation applications. The research outcomes offer the design and casting communities with new capabilities enabling gains in component properties, productivity, rapid component design and manufacturing procedures. These procedures include industrial melt chemical and physical treatments and an ultra rapid Solution and Artificial Aging Heat Treatments. These approaches were not feasible due to problems such as the lack of scientific knowledge on industrial grades of nano Al-Si-X alloys, limited solid solubility of elements, inadequate wear resistance in extreme environments and the lack of physical simulation engineering tools. The patented Universal Metallurgical Simulator and Analyzer (UMSA) Technology Platforms’ capabilities were further developed to expedite Squeeze Casting (SC), Liquid and Semi-Solid melt processing using various pressure profiles for rapid physical simulations of these complex experimental industrial alloys. SC/HPDC UMSA experiments address: liquid and semi-solid chemical and dynamic physical treatments for structure control and elimination of solidification issues; neutralization of impurity elements; high temperature Solution Treatment and Artificial Aging; and elimination of the grain boundary precipitate-free zone that contributes to corrosion. The novel melt’s physical treatments include impact pressure, monotonic pressure and cyclic pressure loading profiles. Several novel as-cast and heat treated structures were developed and comprehensively characterized. Extensive UMSA Platform(s) processing and Thermal Analysis capabilities were enhanced, allowing for significant gains in understanding the link between processing parameters, Thermal Analysis data, and as-cast and heat treated material characteristics. The project utilized leading edge scientific methodologies for development of new cost effective nano and ultra-fine structured cast aluminum materials that will satisfy future fuel economy and emission targets.

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