Abstract

Ten types of .020 inch stainless steel wire were compared using a tensile test. The wires were tested in the as-received condition and after heat treatment at 750°F for eleven minutes. The data were then analyzed statistically using the general linear hypothesis.

In the as-received condition each of four mechanical properties--elastic modulus, 0.2 per cent yield strength, tensile strength, and percent elongation--was found to vary significantly from one type to another.

When subjected to heat treatment, the elastic modulus proved to be the most stable of the four properties, changing only slightly in three cases. There was no significant change in seven of the wires. The 0.2 per cent yield strength increased in six out of ten samples, remained the same in three, and deceased in one. The tensile strength increased in four samples, decreased in three, and showed no change in three. For the per cent elongation there was a decrease in four samples, an increase in two and four remained unchanged.

The elastic modulus and 0.2 per cent elongation are the most important properties to the orthodontist due to their effect on stiffness, strength, and range. Among the wires tested in this study, an increase of 22.9 per cent for stiffness, a 76.8 per cent increase in strength, and a 43.6 per cent increase in range could be obtained simply by wire selection.

For most samples, heat treatment was effective for increasing the 0.2 per cent yield strength. In one of the wires tested the original 0.2 percent yield strength was 176 x 103 psi and heat treatment increased this to 233 x 103 psi, an increase of 32.4 per cent.

The observed changes in properties from the heat treatment were probably due to the relief of internal stresses introduced by cold working the metal during the manufacturing process.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

Jack L. Tomlinson

Second Advisor

J. Milford Anholm

Third Advisor

Steve N. Asahino

Fourth Advisor

Alden B. Chase

Fifth Advisor

John K. Pearson

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1978

Date (Title Page)

6-1978

Language

English

Library of Congress/MESH Subject Headings

Orthodontic Appliances

Type

Thesis

Page Count

vi; 42

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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