METHOD FOR MACHINING FOAM METAL

PROBLEM TO BE SOLVED: To improve the accuracy of a machined surface of a foam metal, and also to smoothly carry out machining operation. SOLUTION: A tray E having the foam metal M put in is charged with water W using a water filling unit 11. The foam metal M immersed in the water W (liquid to be frozen) contains the water in its pores, and its outer surface is covered with the water. In such a state, the foam metal M is frozen using a refrigerating unit 12, and the water contained in the pores and covering the outer surface of the foam metal M comes into the state of ice (frozen layer). After that, the foam metal M entirely covered with the frozen layers is fed to a cutting-off machine 13, and is cut-off by its rotary cutter (cutting-off tool) 13b. Because the ice (solid) in the pores of the foam metal supports skeleton portions (frame portion)( of the foam metal from the outside, cutting-off portions (portions to be machined) are smoothly cut-off without causing any sag due to their plastic deformation. Consequently, a cut-off surface A is flatly finished with high dimensional accuracy. COPYRIGHT: (C)2003,JPO