TITLE:
Creep Function Parameter Analysis for Optimum Design with Calcium Carbonate Nanofiller – Polypropylene Composite
AUTHORS:
Christopher Chukwutoo Ihueze, Chinedum Ogonna Mgbemena, E.E. Nnuka
KEYWORDS:
activation energy, sensitivity parameter, creep rate, creep limit stress level
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.10 No.1,
January
20,
2011
ABSTRACT: This paper is about the use of power law model to fit experimental creep data of PP reinforced
with calcium carbonate nanofiller at 10% optimum volume fraction with a view to characterizing
the new material (PPC2) parametrically. The creep parameters were evaluated for neat (PPC0)
and reinforced PP (PPC2) to establish the influence of reinforcement on the creep variables like
creep rate and creep activation energy. The coefficient parameter A estimated within the stress
level range 13.08MPa-22.88MPa has the range 0.0165-0.0651 while the exponent parameter n
has 0.299-0.370. The creep stress coefficient K and exponent m has the respective values
161.495 and 0.3288 for PPC0 and 1881.4965 and 0.5448 for PPC2. The value of the parameter
p similar to Larson-Miller has the value 4014.1871. Two creep function models used found that
PPC0 has higher activation energy with value 9.3642E-20 J/mol for the stress 13.08MPa and
PPC2 has values for the stresses 13.08MPa, 19.61MPa and 22.88MPa as 5.55998E-
20J/mol,5.4573E-20J/mol and 4.845E-20J/mol respectively. Of the two master curves produced,
that following Larson-Miller parameter is recommended as the relationship between lnσ and
parameter f(σ) is relatively linear and will give better results than the curve assumed to follow
Sherby-Dorn that will give average result.