Volume 5, Issue 9 (October 2008)
Comparison of the Temperature and Pre-Aging Influences on the Low Cycle Fatigue and Thermo-Mechanical Fatigue Behavior of Copper Alloys (CuCoBe/CuCo2Be)
Typically thermo-mechanical fatigue (TMF) loaded components in power plants and steel works are made of copper alloys and are used in different applications (e.g. cooling systems in continuous casting, transformers). So a careful analysis and comparison of the experimental results and microstructure of thermo-mechanical loaded copper components, which are based on a systematic variation of the relevant influence factors, have been conducted to develop empirical models for computing the fatigue life. At specific low cycle fatigue (LCF) and thermo-mechanical fatigue test series on the copper alloys CuCoBe and CuCo2Be, the influence of pre-aging and temperature were investigated by means of the cyclic deformation and lifetime behavior. Based on stress-strain loops from LCF tests at different temperatures and aging conditions a non-linear combined material model was adopted to describe the cyclic deformation behavior. The simulated loading parameters of stress and strain were the basis for the subsequent lifetime simulation. A new energy based damage parameter for copper alloys has been developed to fulfill the requirements of lifetime simulation.