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Scanning Manufacturing Parameters Determining the Residual Stress State in LPBF IN718 Small Parts
Author(s) -
Serrano-Munoz Itziar,
Ulbricht Alexander,
Fritsch Tobias,
Mishurova Tatiana,
Kromm Arne,
Hofmann Michael,
Wimpory Robert C.,
Evans Alexander,
Bruno Giovanni
Publication year - 2021
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.202100158
Subject(s) - residual stress , materials science , rotation (mathematics) , stress (linguistics) , von mises yield criterion , diffraction , distortion (music) , crystallography , neutron diffraction , optics , composite material , geometry , mathematics , structural engineering , physics , finite element method , chemistry , amplifier , linguistics , philosophy , cmos , optoelectronics , engineering
The influence of scan strategy on the residual stress (RS) state of an as‐built IN718 alloy produced by means of laser powder bed fusion (LPBF) is investigated. Two scan vector rotations (90°‐alternation and 67°‐rotation), each produced following two different scan vector lengths (long and short), are used to manufacture four rectangular prisms. Neutron diffraction (ND) and laboratory X‐ray diffraction (XRD) techniques are used to map the bulk and surface RS state, respectively. The distortion induced upon removal from the baseplate is measured via profilometry. XRD measurements show that the two long scan vector strategies lead to higher RS when compared with the equivalent short scan vector strategies. Also, the 67°‐rotation strategies generate lower RS than their 90°‐alternation counterparts. Due to the lack of reliable stress‐freed 0references, the ND results are analyzed using von Mises stress. In general, ND results show significant RS spatial non‐uniformity. A comparison between ND and distortion results indicates that the RS component parallel to the building direction ( Z ‐axis) has a predominant role in the Z ‐displacement. The use of a stress balance scheme allows to discuss thed 0variability along the length of the specimens, as well as examine the absolute RS state.