Manufacturability and material properties of the bimetallic material of stainless steel 316L and nickel-based superalloy Inconel 718 fabricated via laser-based powder bed fusion
Valtonen, Eetu (2026-03-06)
Manufacturability and material properties of the bimetallic material of stainless steel 316L and nickel-based superalloy Inconel 718 fabricated via laser-based powder bed fusion
(06.03.2026)
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.
avoin
Julkaisun pysyvä osoite on:
https://urn.fi/URN:NBN:fi-fe2026033124697
https://urn.fi/URN:NBN:fi-fe2026033124697
Tiivistelmä
Additive manufacturing (AM), also known as industrial three dimensional (3D) printing, is a modern production method which manufactures a workpiece directly from a digital model, often layer by layer. This method allows for designs and geometries which are prohibitively complex to manufacture using conventional techniques. Bimetallic objects are defined as consisting of two metals that are joined together and AM of bimetals is the practice of using AM techniques to produce bimetallic objects. Stainless steel 316L (316L) is a widely used cost effective alloy with good material properties for industrial applications. Nickel-based superalloy Inconel 718 (IN718) is a high-performance superalloy used in demanding conditions. The bimetallic combination of 316L-IN718 is a high-performance material combination for nuclear energy and aerospace applications, for which additive manufacturing has been proposed as a viable method of production.
The aim of this thesis is to establish an understanding of the additive manufacturing of bimetallic 316-IN718 via laser-based powder bed fusion. The thesis aims to study the additive manufacturing process for bimetallic 316L-IN718 and the properties of 316L-IN718 manufactured by laser-based powder bed fusion. This includes the study of the parameters used to manufacture IN718 onto an additively manufactured 316L substrate as well as the study of manufactured 316L-IN718 workpieces in laboratory measurements. Research is conducted to determine the manufacturability of the bimetallic combination of 316L-IN718, as well as determine the effect of an IN718 focused heat treatment plan on the properties and characteristics of the bimetallic combination.
Main findings include the successful additive manufacture of 316L-IN718 via laser-based powder bed fusion, as well as the influence of the IN718 heat treatment on the bimetallic material properties: porosity, microstructure, geometrical accuracy, hardness, corrosion rate. Hardness and corrosion rate results are compared to values found in literature and observed behavior is compared with theoretical understanding. Heat treatment is observed to cause a notable increase to the hardness of IN718 while having a minor negative effect on the hardness of 316L, with the interface gaining a minor positive effect. Heat treatment is observed to increase corrosion rate for IN718, 316L and the interface.
Future research is suggested to focus on further study of the corrosion behavior as well as dilatometry, fatigue investigation, computed tomography, residual stress analysis and helium leak tests. Overall, this thesis provides an overview of laser-based powder bed fusion, the bimetallic combination of 316L-IN718 as well as its properties and characteristics when manufactured via laser-based powder bed fusion.
The aim of this thesis is to establish an understanding of the additive manufacturing of bimetallic 316-IN718 via laser-based powder bed fusion. The thesis aims to study the additive manufacturing process for bimetallic 316L-IN718 and the properties of 316L-IN718 manufactured by laser-based powder bed fusion. This includes the study of the parameters used to manufacture IN718 onto an additively manufactured 316L substrate as well as the study of manufactured 316L-IN718 workpieces in laboratory measurements. Research is conducted to determine the manufacturability of the bimetallic combination of 316L-IN718, as well as determine the effect of an IN718 focused heat treatment plan on the properties and characteristics of the bimetallic combination.
Main findings include the successful additive manufacture of 316L-IN718 via laser-based powder bed fusion, as well as the influence of the IN718 heat treatment on the bimetallic material properties: porosity, microstructure, geometrical accuracy, hardness, corrosion rate. Hardness and corrosion rate results are compared to values found in literature and observed behavior is compared with theoretical understanding. Heat treatment is observed to cause a notable increase to the hardness of IN718 while having a minor negative effect on the hardness of 316L, with the interface gaining a minor positive effect. Heat treatment is observed to increase corrosion rate for IN718, 316L and the interface.
Future research is suggested to focus on further study of the corrosion behavior as well as dilatometry, fatigue investigation, computed tomography, residual stress analysis and helium leak tests. Overall, this thesis provides an overview of laser-based powder bed fusion, the bimetallic combination of 316L-IN718 as well as its properties and characteristics when manufactured via laser-based powder bed fusion.