초록 ▼

A sheet of material is held in a die opposite a forming surface of the die, and gas pressure is applied to both sides of the sheet. The pressure creates a compressive stress in the sheet thickness direction sufficient to cause plastic flow. By maintaining the pressure higher on the side of the sheet

A sheet of material is held in a die opposite a forming surface of the die, and gas pressure is applied to both sides of the sheet. The pressure creates a compressive stress in the sheet thickness direction sufficient to cause plastic flow. By maintaining the pressure higher on the side of the sheet opposite to the forming surface, the sheet bends and expands toward the die forming surface. This pressure differential can be increased as necessary to bend the sheet into the crevices which make up the details of the forming surface. The sheet may be heated during forming to lower the compressive stress which is required to cause it to flow plastically.

대표청구항 ▼

A method of compression forming a sheet of material having plastic properties, comprising: holding said sheet opposite a surface of a die; applying fluid pressure concurrently to both sides of said sheet to create a compressive stress in said sheet in the through thickness direction which at least e

A method of compression forming a sheet of material having plastic properties, comprising: holding said sheet opposite a surface of a die; applying fluid pressure concurrently to both sides of said sheet to create a compressive stress in said sheet in the through thickness direction which at least equals the stress at which the material begins to flow plastically; maintaining said pressure higher on one side of said sheet than on the other side so that said sheet bends toward said surface and forms plastically by said compressive stress against the said surface of said die.