METHOD AND APPARATUS FOR DUAL SUPERPLASTIC FORMING OF METAL SHEETS

Abstract

A pair of sheets of a metal capable of exhibiting superplasticity, such as Titanium, are placed in overlapping relationship and the peripheral edges of the sheets are joined, such as by welding, to provide a gas impervious seal. The joined metal sheets are lowered into a press so that they extend vertically between a pair of horizontally spaced apart, vertically extending preheated ceramic dies. The dies are previously transferred inside insulating shrouds from a preheater station before being loaded into the press. At least one of the dies is moved horizontally toward the other one of the dies so that the joined metal sheets are positioned closely adjacent to the dies. As a result, the metal sheets are heated to a predetermined temperature at which they are capable of exhibiting superplasticity. Thermostatically controlled heating platens behind the dies offset any heat losses in the dies as they radiate energy to the joined metal sheets. Thereafter a pressurized gas, such as Argon, is introduced between the joined metal sheets so that they are pushed outwardly against corresponding ones of the dies and formed against the same. At least one of the dies is thereafter moved horizontally away from the other one of the dies and the formed metal sheets are lifted out of the press. The formed metal sheets are then transferred to a cooling station. Once cooled, the formed metal sheets are cut apart to produce two or more formed pieces.

Source: Google Patents

35 USC §181 Secrecy Order

Inventor

• 1GILBERT C. CADWELL