Usanee Peungpaiboon. The potential of high copper alloys as alternative materials for post-and-core application . Master's Degree(Prosthodontics). Mahidol University. : Mahidol University, 2004.
The potential of high copper alloys as alternative materials for post-and-core application
Abstract:
The purposes of this study are to compare mechanical properties and corrosion
resistance of three copper alloys (CuAl, CuAlNi, CuZn), and to determine the
potential of these alloys for further development as post-and-core materials. Six
tensile bars and six square plated specimens of each alloy were prepared and tested
according to ISO1562 for mechanical properties and ISO 10271 for corrosion
resistance. 0.2 percent proof stress, modulus of elasticity, percentage elongation after
fracture, and tensile strength were calculated from load-displacement curve obtained
from the record chart of the Universal Testing Machine (UTM). One way ANOVA
and Tukey HSD were used to determine the difference in properties among the alloys.
Potentiodynamic technique was selected to test the corrosion resistance of the alloys.
The test was performed in 37ºc de-aerated 0.9% NaCl solution. The characteristics of
the potentiodynamic curve of each alloy were compared.
All alloys were not different in percentage elongation, while 0.2 percent proof
stress and ultimate tensile strength of CuAl was significantly higher than those of
CuAlNi and CuZn. Although the moduli of elasticity value were not valid in this
study, a pilot study showed a promising value suitable for post-and-core application.
Only 0.2 percent proof stress and ultimate tensile strength were not satisfying as
criteria for a good post and core material. Potentiodynamic curves of CuAlNi showed
a longer passive region than that of CuAl, while that of CuZn did not show any
passive region. In conclusion, CuAl and CuAlNi alloys have a potential for further
development as good post-and-core materials.