Properties improvement of thixoformed parts by Liquid Hot Isostatic Pressing process

Abstract

Introduced almost a century ago as a concept the hot isostatic pressing process has been widely and successfully used to treat aluminum casting for niche markets.

The reason why this post-processing idea is not applied to mass production is costs. In fact the media used to apply pressure on components to be treated in a vessel at high temperature,where the material softens and compacts uniformely, is a gas. Long treatment times added to highly risky plants are adding costs to the processing route.
Recently the partnership between Teksid and Idra is on the way to industrialize a new hot isostatic process, called Liquid Hot Isostatic Pressing – LHIP where the media used to apply pressure on the components to be treated is a liquid salt.
With this technology it is reasonable to think that mass production post-treatment of automotive aluminum castings will be achieved, with the goal of having stronger parts with higher fatigue properties and reduced scrap level in the foundry process production chain.
This paper describes the effect of LHIP on aluminum thixoformed castings, outlining the beneficial process effects on the mechanical properties.