By: Kirk Norasak C0-Authors: Jonathan Ball Eric Lucas Dr. John DesJardins University of...
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Transcript of By: Kirk Norasak C0-Authors: Jonathan Ball Eric Lucas Dr. John DesJardins University of...
Wear Testing Performance of Proton Irradiated Ultra High
Molecular Weight PolyethyleneBy: Kirk Norasak
C0-Authors: Jonathan Ball Eric Lucas
Dr. John DesJardins
University of Kentucky-Home Clemson University-REU Program
What do these pictures have in common?
Introduction The proton irradiation of materials can occur
during space flight as a result of solar flares, and during cancer treatment therapies where proton beam therapy is prescribed.
Due to cross-linking of the free-radicals in the polymer during irradiation, mechanical properties such as wear resistance are known to change with gamma irradiation, but the effect of proton irradiation is unknown.
Motivation To understand the affects of Proton
irradiation on Hip Joint Replacement UHMWPE.
Ex. Cancer patients, and Radiation Shielding.To determine if Space radiation doses will
affect the material properties of the UHMWPE.
Continuation of Last Years Project AbstractFollowing irradiation, uniaxial tensile testing
and thermal testing using Differential Scanning Calorimetery (DSC) and Dynamic Mechanical Analysis (DMA) were performed. Results show small but significant changes in several material properties between the Control (0 Gy) and 35 Gy samples, indicating that proton irradiation could have a detrimental effect on the long term performance of UHMWPE in both medical and space flight applications.
ObjectivesTo characterize Proton irradiated UHMWPE
for wear resistance using an industry standard pin-on-disk wear testing system.
Program and improve the pin-on-disk wear testing system.
Experimental Irradiated the UHMWPE at doses from 0 Gy to 35 Gy.Machined the UHMWPE into pin test samples.Used the ASTM standard to clean the samples. Used a grinding wheel to polish the 316 L Stainless Steel
pucks to a surface roughness (Ra value) of 70 nm.Used a Surface Profilometer to measure the surface
roughness Ra value of the UHMWPE pins and 316 L Stainless steel pucks.
Created a program in SolidWorks to calculate the pair of angles to make a circle on the Orthopod.
Wear test UHMWPE using the Orhopod pin-on-disk system.
Machined Pins
ASTM Cleaning Pins
Grinding the Pucks
Surface Profilometer
Solidworks Circle Program
Orthopod Wear Testing
Orthopod Wear testing cont.
Orthopod Wear Testing Cont.
Results of Wear testing…..Pending Based on Gamma irradiation, the UHMWPE
should have a increased wear resistance.
Future WorkTo continue working out the problems with
the wear testing system.To figure out a way to grind the pucks
without hand grinding.To work on a vacuum chamber that will not
only subject the samples to low pressure, but low temperatures as well while being irradiated.
Acknowledgements I would like to give my thanks to the following
people:
Casper Wright-Walker Dr. Kennedy