Session: MF-17-02 Advanced and Additive Manufacturing and Material Technologies (joint with D&A)

Paper Number: 84785

84785 - Ductile Damage Model Development and Validation of 316l Laser Powder Bed Fusion Steel Under Multiaxial Stress Conditions 

Laser powder bed fusion (LPBF) is an additive manufacture technique which builds components up in layers from a powder feedstock, using a scanning laser to selectively sinter the powder into the required shape. When used for metals, such as 316L stainless steel, LPBF can create complex components with properties not dissimilar to those achieved with more conventional manufacturing methods.

The process of LPBF can often introduce defects into the structure of a part, since the powder may not fully melt and leave holes, or pores, in the sample. Excessive laser power may also cause the powder to vaporise and create pores. In whatever manner these pores are formed, they can significantly impact the properties of the finished component.

 

Since pores and small defects pre-exist in LPBF components, the void growth and ductile fracture behaviour of LPBF components under multiaxial stress conditions needs to be characterised and predicted. In this work, notched bar tensile tests have been permed on samples with a range of notch acuities and hence multiaxial stress states. These tests have enabled ductile damage models to be calibrated and finite element simulations of the notched bar tests performed. The comparison between the experimental results and finite element predictions will enable model validation.

Presenting Author: Catrin Mair Davies Imperial College London

Presenting Author Biography: Reader in structural Integrity of alloys at Imperial college London.

Authors:

Theo Hales Imperial College London
Tobias Ronneberg Imperial college london
Paul Hooper Imperial college london
Catrin Mair Davies Imperial College London