Method for determining the proper progress of a superplastic forming process

摘要

A method of determining the progress of a superplastic formation process that uses controlled gas-mass flow rate of inert gas to form a part from generally one or more sheets of superplastically formable material, a process that may include selective diffusion bonding of the sheets together. The method includes using the expected initial conditions of the process to calculate a family of constant volume curves plotted on a graph of pressure versus cumulative gas-mass and then comparing the actual pressure and cumulative gas-mass that occurs during the process to determine the health of the process and to determine when the process has successfully completed. The comparison may be performed manually or automatically with a computer which has been programmed to characteristic and non-characteristic progress curve portions.