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Corrosion and fretting simulation

To analyze corrosion processes, such as fretting corrosion at hip implants, a fatigue test in compliance with ISO 7206-4 is carried out. To do this, the implant is fixed in an embedding medium. The alignment of the implant is carried out with 10 adduction and 9 flexion. A sinusoidal oscillating force of 2300N is applied to the prosthesis by a servo-hydraulic testing machine (MTS Minibionix). The testing frequency can be varied; for testing according to ISO 7206-4 the frequency lies between 4Hz and 30Hz. The implant is immersed in heated sodium chloride solution or heated diluted bovine serum. Two methods are available to detect corrosion products. To obtain qualitative results, the open corrosion potential of the implant can be measured using a reference electrode. For quantitative results, the amount and composition of corrosion products can be determined using the hr-ICPMS method. In addition, it is possible to apply other load profiles than the one described in ISO 7206. Investigations with rising load levels or varying test frequencies can be carried out.

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