Computer Simulation Analysis on the Machinability of Alumina Dispersion Enforced Copper Alloy for High Performance Compact Heat Exchanger

Feasibility study on a HTGR-GT (High Temperature Gas cooled Reactor-Gas Turbine) system is examining the application of the high strength/high thermal conductivity alumina dispersed copper (AL-25) in the ultra-fine rectangle plate fin of the recuperator for the system.However, it is very difficult to manufacture a ultra-fine fin by large-scale plastic deformation from the hard and brittle Al-25 foil.Therefor, in present study, to establish the fine fin manufacturing technology of the AL-25 foil, it did the processing simulation of the fine fin first by the large-scale elasto-plastic finite element analysis(FEM) and it estimated a forming limit.Next, it experimentally made the manufacturing equipment where it is possible to do new processing using these analytical results, and it implemented a manufacturing experiment on the AL-25 foil.With these results, the following conclusion was obtained.(1) It did the processing simulation to manufacture a fine rectangle fin (fin height×pitch×thickness, 3 mm×4 mm×0.156 mm) from AL-25 foil (Thickness=0.156 mm) by the large-scale elasto-plastic FEM using the double action processing method. As a result, the manufacturing of a fine rectangle fin found a possible thing in the following condition by the double action processing method. It made that 0.8 mm and 0.25 mm were a best value respectively in the R part and the clearance between dies by making double action processing examination equipment experimentally and implementing a manufacturing examination using this equipment.(2) It succeeded in the manufacturing of the fine fin that the height×pitch×thickness is 3 mm×4 mm×(0.156 mm±0.001 mm) after implementing a fine rectangle fin manufacturing examination from the AL-25 foil.(3) The change of the process of the deformation and the thickness by the processing of the AL-25 foil which was estimated by the large-scale elasto-plastic FEM showed the result of the processing experiment and good agreement.This way of analyzing made an effective thing clear as the processing estimation of the manufacturing practicalizing of the fine fin of the difficulty process-ability material by the double action processing method from this study.