Structural Integrity of an Electron Beam Melted Titanium Alloy

Area of Science:

• Materials Science and Engineering
• Additive Manufacturing
• Mechanical Testing

Background:

• Advanced manufacturing, including "3D printing" of metals like Electron Beam Melting (EBM), enables complex geometries but results in variable microstructures.
• Assessing the relationship between process variables, microstructure, and mechanical properties is crucial for implementing these components, especially in demanding applications like gas turbines.
• Traditional mechanical testing is challenging for small, intricate parts produced by EBM due to difficulties in obtaining representative specimens.

Purpose of the Study:

• To develop and validate strategies for the safe implementation of advanced manufactured components in gas turbine applications.
• To investigate the structural integrity and mechanical response of Ti-6Al-4V variants produced via various routes, including EBM.
• To demonstrate the utility of the small punch (SP) test for characterizing materials with complex geometries.

Main Methods:

• Application of the small punch (SP) test to Ti-6Al-4V samples manufactured using Electron Beam Melting (EBM) and other processing routes.
• Analysis of microstructural variations resulting from different thermal cycles during EBM.
• Correlation of SP test results with material structural integrity and mechanical behavior.

Main Results:

• The small punch (SP) test successfully sampled miniaturized specimens from discrete locations within thin-walled components.
• Characterization across complex geometries was achieved, revealing variations in mechanical response.
• The study provided data supporting the assessment of structural integrity for advanced manufactured materials.

Conclusions:

• The small punch (SP) test is a viable technique for comprehensive mechanical characterization of additively manufactured components with intricate geometries.
• Validation strategies using the SP test can facilitate the safe integration of EBM-processed Ti-6Al-4V into gas turbine engines.
• Understanding the link between processing, microstructure, and mechanical properties is essential for qualifying advanced manufacturing technologies.