612 難加工性アルミナ分散銅の細密フィン折り加工試験とその解析(塑性加工シミュレーション)(OS.3 弾塑性材料のシミュレーションと実験)

Abstract

In order to improve system performance of HTGR-GT(High Temperature Gas cooled Reactor- Gas Turbine) system, high strength/ high thermal conductivity alumina dispersed copper material(AL-25) is very attractive material for the application to the fine rectangular plate fin of the recuperate in HTGR-GT. However, it is believed to be difficult to process AL-25 to the fine rectangle plate fin mainly due to its brittleness. In present study, large scale deformation simulation of AL-25 thin plate under the fine fin process was performed by finite element method (FEM) to determine the best fin processing technique for the recuperate plate fin, and on the basis of these results, double action type plate fin processing device was fabricated and tested its processing performance with AL-25 thin plate specimens. The following conclusions were determined; (1) Process simulation of rectangular fine plate of 3mm height and 4mm pitch with 0.156mm thickness was performed by FEM and testified the effectiveness of the double action type plate fin processing technique for present purpose. With these results, the best processing condition of radius of the dies and clearance was derived as 0.8mm and 0.25mm, respectively. (2) In these process conditions, processing test of the rectangular fine plate of 3mm height and 4mm pitch was made successfully with 0.156mm thin plate AL-25 without crack and fracture. (3) The process simulation results of the change in thickness of thin plate AL-25 after processing shows very good agreement with the measuring data of the rectangular plate fins. These results indicated that double action process and simulation technique in present study can be applicable to process fine rectangular plate fin with vely brittle materials as AL-25.