Study On Forming Technology With Ceramic Granules As Press Transfer Medium

Drawing technology with solid granules as load transfer medium is one category of soft tool forming technologies, since solid granules are characteristic of favorable fluidity and almost non-condensability of solidity.Ceramic granules with different diameters were selected as load transfer medium to instead of punch and cavity die, and forming experimentation of columnar parts in two technical conditions were carried out in this thesis. The results of experiments show that the transition section from the bulging region to the drawing region is easy to be ruptured in the case of the solid granules as punch, and the forming limitation of sheet increases along with the diameter decreasing when the quantity of ceramic granule is constant. While the diameter of ceramic granule is larger than certain critical value, the forming limitation of sheet will not increase. Moreover, it is found that the forming limitation of sheet improves observably when the quantity of ceramic granule decrease during forming process, on the condition of the diameter of ceramic granule is constant.On the conditions of the solid granules as cavity die, the fitability of sheet can be improved by increasing the diameters of ceramic granules under the constant reverse pressure, and for the ceramic granules of same diameter done by increasing the reverse pressure. However, the surface quality of part and the formability of sheet will decrease along with the increasing of reverse pressure.