Residual Stress Evaluation of Metal AM Components

 

CRP year	2017
Budget	£115k
Project Reference No.	32299
Technical Lead	Bochuan Liu
AM process & materials used	Laser powder bed fusion (In718)

Summary

Laser powder bed fusion AM has a unique thermal cycle that involves a steep thermal gradient up to the materials’ melting point, rapid solidification, and then re-melting on subsequent layers. This causes residual stress to build up in the part which is a significant issue given its effect on distortion, reduced performance and premature failure of the part. This CRP project:

• Measured the residual stress distribution in AM benchmarking features using electronic speckle pattern interferometry (ESPI) hole-drilling as a comparison to conventional strain gauge hole-drilling
• Studied the influence on the stress from altering the build parameter strategies
• Investigated the relationship between stress distribution and distortion on benchmarking features (see Figure 1)
• Generated a data library for AM process simulation

 

DELIVERABLES

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