TITLE:
Indentation Creep Behavior and Microstructure of Cu-Ge Ferrites
AUTHORS:
Hesham Mohaned Zaki, Ali Mohamed Abdel-Daiem, Yahia Ibrahim Swilem, Farid El-Tantawy, Fahad Masoud Al-Marzouki, Ahmed Abdallah Al-Ghamdi, Saleh Al-Heniti, Farag Said Al-Hazmi, Talal Sadaka Al-harbi
KEYWORDS:
Ferrites, Indentation Creep, Microstructure
JOURNAL NAME:
Materials Sciences and Applications,
Vol.2 No.8,
August
9,
2011
ABSTRACT: Cu-Ge ferrite was prepared using the standard ceramic method. The creep rate of polycrystalline Cu1+xGexFe2-2xO4 ferrite has been measured as a function of time at room temperature. It is found that the indentation length increases with the increase of both time and applied load. A regime of individual creep curves is observed for the first and second stages. It is not possible to record the third stage of the curve as usually happened in an ordinary creep test, because fracture of the samples does not occur. The slope is found to increase with increasing germanium and copper content in the steady state region. The high value of n (stress exponent factor) indicates that the dislocation creep is the dominate mechanism. The porosity arrangements developed within the specimens were examined using optical microscope. The results are discussed with regard to models describing the role of the steady state creep rate of metals. The morphology of the samples shows that the porosity is increased by increasing both copper and germanium ions.