Presented by: Dr. Joseph Tunick Strauss—HJE Company, Inc., USA and Stewart Grice—Hoover & Strong, Inc., USA

All conventional metals and alloys are comprised of grains: entities of atoms sharing the same crystallographic orientation. Grain size is an important attribute in all metals as it influences mechanical properties and the attainable surface finish quality, an important factor in jewelry manufacturing. Small grains benefit both of these desired properties; therefore, controlling grain size and, in particular, inhibiting grain growth are essential to optimizing the final material.

There has been recent interest in hot isostatic pressing (HIPing) of both cast and powder metallurgy parts as a mechanism to 'heal' internal porosity. Part of this work identified the possible inhibition of grain growth through HIPing. This paper will investigate this further by comparing the grain-growth response of samples heated under ambient pressure with samples heated under an externally imposed isostatic pressure.

Authors: Dr. Joseph Tunick Strauss, Stewart Grice