2814 爆発成形法によるアルミニウム合金の張出し成形(S36-1 高エネルギー加工(1),S36 高エネルギー加工)

抄録

In recent years, lightening the material of the car body has been attempted for fuel cost reduction. The aluminum alloy has been used as a countermeasure. However, the forming limit of aluminum alloy is less than steel. Therefore, damage ofthe aluminum alloy happens when the car body is formed using conventional punching methods. However, since aluminum alloy has a special feature, when the strain rate exceeds 1000/s, we proposed use of explosive forming method in which strain rates much more than 1000/s can be obtained. Common practice of explosive forming includes the explosion of an explosive in a pressure vessel filled with water. A purpose of our study is examining the forming limit of aluminum alloy plate. In the experiments carried out, the quantity of explosive, the so-called stand off distance and water vessel were changed. Two types of water vessels were used in these experiments ; closed metal vessel and paper vessel. The metal plate is deformed by the underwater shock wave at a speed of several hundred m/s. However the deformation speed of the plate due to expansion of detonation gas is in the order of a few ten m/s. The effects of this gas expansion pressure have been explored.