Studying the Properties of CoCrMo Alloys (F75) Doped Ge Using (Powder Metalluregy) Technique

Abstract

Cobalt chromium alloys are one of the best alloys used for biomedical applications due to their good wear resistance, high mechanical properties, acceptable bio-compatibility and high corrosion resistance. This study aims to investigate the effect of germanium additions(0.5, 1 and 1.5 wt%) on properties of CoCrMo (F75) alloy prepared using powder metallurgy technique. The corrosion, wear and compressive behavior were investigated using different examination and test including mechanical test (hardness, compression and wear) and electrochemical test (open circuit and potentiodynamic polarization). The results revealed that the addition of Ge has a notable effect on the porosity of sintered CoCrMo causing decreasing in porosity. The hardness increases when increases Ge addition. Also the addition of Ge increases the compression strength, and it's increased as additives increase. On the other hand the wear rate of CoCrMo (with and without additives) increases as the time and load increase, however wear resistance increases with the addition of Ge element and it's increased as Ge additives increase. The corrosion resistance of CoCrMo alloy improved after the addition of Ge in artificial saliva and Hank's solution. Also the corrosion resistance increase as Ge additives increase. The corrosion current for most used alloys in artificial saliva is lower than that for Hank's solution.