Alpha case contamination of Titanium alloys results from oxygen or nitrogen pick-up during heat treatment. This brittle surface structure is prone to microcracking, and reduces the metal's performance and fatigue properties.
A Metaltest Alpha Case evaluation will reveal the depth and composition of the alpha case structure. The image at the right is a micrograph of Titanium 6AL-4V with a cascading alpha case effect. While alpha case may be prevented by heat treating in a vacuum, most often it is simply removed by mechanical grinding or chemical etching. A Metaltest Alpha Case evaluation will show you how much metal must be removed.
Alpha case evaluation is performed according to customer drawings or specifications.
Applicable Specifications
Alpha Case evaluation of titanium contamination of surface microstructure by gasses is performed according to prime contractor or industry specifications.