Hot Isostatic Press

A hot isostatic press subjects a material, typically a metal or ceramic part, to both high temperature and high pressure at once, applied equally from every direction by an inert gas inside a sealed chamber, in order to eliminate internal voids and porosity and bond the material into a fully dense, uniform solid. Researchers at the Battelle Memorial Institute in the United States developed the technique in the mid-1950s, originally to bond dissimilar metals together for nuclear fuel element cladding, a task that required uniform pressure from all sides rather than the one-directional pressure of a conventional forging or pressing operation. Hot isostatic pressing went on to become a standard way to remove porosity from cast metal parts, consolidate metal or ceramic powders into finished components, and improve the reliability of critical parts such as jet engine turbine blades.