Experimental Investigation on Process Signature for EDM Processes

摘要

In recent years,the term"process signature"has been introduced by different scientists.Within the framework of determining process signatures,the interaction between material loads resulting in material modifications should be investigated.During recently this idea is adopted to the EDM process.Therefore,as a further step towards this goal,in this work the interaction between the applied thermal loads(including temperature field as well as temporal temperature gradients)and the induced modifications in form of phase transitions and change in the grain size in the heat affected zone(HAZ)during single discharge experiments were analyzed.Due to the nature of the EDM process,namely its high frequency as well as high local and temporal gradients of the applied thermal loads,the in-situ measurement of the thermal loads is not always straightforward and accurate enough.Thereby,the determination of applied thermal loads has been done by using a heat transfer simulation model.Using the obtained results from the experiment and simulations,the microstructure modifications in the HAZ of an eroded workpiece are analyzed,with respect to the temperature gradients induced during a single discharge experiment.