Characteristics of Cobalt Chromium Alloy Surfaces Finished Using Magnetic Abrasive Finishing

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Material Information

Title:
Characteristics of Cobalt Chromium Alloy Surfaces Finished Using Magnetic Abrasive Finishing
Physical Description:
1 online resource (132 p.)
Language:
english
Creator:
Graziano, Arthur A
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Mechanical Engineering, Mechanical and Aerospace Engineering
Committee Chair:
GREENSLET,HITOMI
Committee Co-Chair:
IFJU,PETER G
Committee Members:
SCHUELLER,JOHN KENNETH
MYERS,MICHELE V
SCHMITZ,TONY LAVAUN

Subjects

Subjects / Keywords:
abrasive -- chromium -- cobalt -- finishing -- freeform -- lay -- magnetic -- surface -- texture -- wettability
Mechanical and Aerospace Engineering -- Dissertations, Academic -- UF
Genre:
Mechanical Engineering thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
Freeform surfaces, including the femoral components of knee prosthetics, present a significant challenge in manufacturing. The finishing process is often performed manually, which leads to surface finish variations. In the case of knee prosthetics, this can be a factor leading to accelerated wear of the polyethylene tibial component. The wear resistance of polyethylene components might be influenced by not only the roughness but also the lay of femoral component surfaces. This study applies Magnetic Abrasive Finishing (MAF) for nanometer-scale finishing of cobalt chromium alloys, which are commonly used in knee prosthetics and other freeform components. First, using flat disks as workpieces, this paper shows the dominant parameters for controlling the lay in MAF and demonstrates the feasibility of MAF to alter the lay while controlling the surface roughness. The manually finished disk surfaces (with roughness around 3 nm Sa), consisting of random cutting marks,were compared to MAF-produced surfaces (with roughness between 2-3 nm Sa) with various lays. Tests using deionized water droplets show that the lay influences the wetting properties even if the surface roughness changes by no more than a nanometer. Surfaces with unidirectional cutting marks exhibit the least wettability, and increasing the cross-hatch angle in the MAF-produced surfaces increases the wettability. Surfaces consisting of short, intermittent cutting marks were the most wettable by deionized water. Coefficient of friction tests in deionized water show a decrease in coefficient of friction for MAF-processed surfaces. The MAF process is extended to finish femoral knee components. The previously mentioned surface lays were reproduced on the freeform condyle surfaces of the femoral knee components. The as-received surface consisted of several protuberances (with roughness of 8.4/2.3 nm Sa at 10X/40X),which were removed after the MAF process (to a roughness of 5.5/2.7 nm Sa at 10X/40X). It was verified that the MAF process does not alter the form accuracy of the freeform surface,suggesting that this process can be used to control the surface lay and surface roughness of freeform surfaces.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Arthur A Graziano.
Thesis:
Thesis (Ph.D.)--University of Florida, 2013.
Local:
Adviser: GREENSLET,HITOMI.
Local:
Co-adviser: IFJU,PETER G.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-12-31

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2013
System ID:
UFE0046150:00001