| 摘要 |
PURPOSE:To form easily and accurately a member having durability, impact resistance and a large coefft. of surface friction by adhering tentatively ceramic splinters to the surface of a superplastic alloy after primary forming and subjecting the alloy to press- forming in the prescribed straining speed region in a die while heating the alloy to a prescribed temp. region. CONSTITUTION:The SiC splinters 2 are tentatively stuck by a self-adhesive agent to the surface of the primarily formed cylindrical blank material 1 consisting of, for example, a Zn-Al superplastic alloy contg. fine eutectoid crystal grans. The blank material is heated in the lower die 3 to about 250+ or -1 deg.C temp. region to be determined by the compsn. and structure of said alloy. The upper die 4 is then lowered at 2mm./min speed at which superplasticity is developed in the axial direction to xert the load to the blank material, thereby forming compressively the material to a disk shape. The splinters 2 are thereby compressed between the inside peripheral surface of the die 3 and the peripheral surface of the balnk material 1' in the final stage of the forming process. The splinters 2 are securely embedded to the surface of the material 1' in the partly exposed state by the plastic flow exhibited by the alloy in this stage. The member having the large coefft. of surface friction is thus obtd. |
