Masters Theses


Uma Ramadorai

Keywords and Phrases

Aluminum matrix surface composites; Composites by design


"Engineered aluminum surface metal matrix composites were created by incorporating ceramic particles like WC, SiC, Al₂O₃, WC + SiC, and a mixture of hard particle with solid lubricant, SiC + MoS₂, using friction stir processing. Processing parameters were studied and optimized to produce uniform distribution of these particles in the near surface region. Optical and scanning electron microscopy showed that the stirred region developed as deep as the pin probe. Proper tooling enables the thickness of the surface composite to be controlled from thin (2 mm) to orders of magnitude thicker (10 mm) than conventional coatings. The composite is defect free and forms a graded metallurgical bond with the underlying surface. No interface is developed between the composite zone and the base material. Study of properties such as hardness of the discontinuously reinforced surface composite, microstructural stability, wetting, stiffness and other mechanical properties showed commendable increase. Volume fraction, particle size and properties, and process parameters were observed to have a major effect on the resulting material properties. Control over the aforementioned variables was achieved leading to creation of surface metal matrix composites by design"--Abstract, page iii.


Newkirk, Joseph William

Committee Member(s)

Kohser, Ronald A.
Smith, Jeffrey D.


Materials Science and Engineering

Degree Name

M.S. in Metallurgical Engineering


University of Missouri--Rolla

Publication Date

Summer 2005


xiii, 79 pages

Note about bibliography

Includes bibliographical references (pages 73-78).


© 2005 Uma Ramadorai, All rights reserved.

Document Type

Thesis - Restricted Access

File Type




Subject Headings

Aluminum alloys -- Metallurgy
Friction welding

Thesis Number

T 8781

Print OCLC #


Electronic OCLC #


Link to Catalog Record

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