Mapping of residual stresses in as-built Inconel 718 fabricated by laser powder bed fusion : A neutron diffraction study of build orientation influence on residual stresses

• Manufacturing of functional (ready to use) parts with the powder bed fusion method has seen an increase in recent times in the field of aerospace and in the medical sector. Residual stresses (RS) induced due to the process itself can lead to defects like cracks and delamination in the part leading to the inferior quality of the part. These RS are one of the main reasons preventing the process from being adopted widely. The powder bed methods have several processing parameters that can be optimized for improving the quality of the component, among which, build orientation is one. In this current study, influence of the build orientation on the residual stress distribution for the Ni-based super-alloy Inconel 718 fabricated by laser-based powder bed fusion method is studied by non- destructive technique of neutron diffraction at selected cross-sections. Further, RS generated in the entire part was predicted using a simplified layer by layer approach using a finite element (FE) based thermo-mechanical numerical model. From the experiment, the part printed in horizontal orientation has shown the least amount of stress in all three directions and a general tendency of compressive RS at the center of the part and tensile RS near the surface was observed in all the samples. The build with vertical orientation has shown the highest amount of RS in both compression and tension. Simplified simulations results are in good agreement with the experimental value of the stresses. © 2020 The Authors

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Bearbetnings-, yt- och fogningsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Manufacturing, Surface and Joining Technology (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Annan materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Other Materials Engineering (hsv//eng)

Nyckelord

Additive manufacturing

FEM

Neutron diffraction

Residual stresses

Superalloys

Fabrication

Nickel alloys

Nondestructive examination

Compression and tension

Experimental values

Layer-by-layer approaches

Neutron diffraction studies

Ni-based superalloys

Non-destructive technique

Processing parameters

Thermo-mechanical

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)