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Where are all the 3D printers we were promised?

3D printing: a solution for long-gone industrial parts

Annalisa Plaitano, science communicator
On March 31st, 2021 |
2 mins reading time
5
3D printing: a solution for long-gone industrial parts

    Fabien Szmytka
    Fabien Szmytka
    Researcher at ENSTA Paris (IP Paris)
    Key takeaways
    • 3D printing is increasingly used in the academic world to help research.
    • Fabien Szmytka, researcher at the ENSTA Paris, uses this technology to study properties and microstructure of metallic materials.
    • He conducts tests on complex structures which are close to the geometry of industrial mechanical parts.
    • The objective of this research is to provide concrete solutions to repair large metallic parts for partners from the energy, transportation and aeronautic sectors (like EDF and SNCF).

    Could you explain what 3D print­ing is and who uses it?

    Fabi­en Szmyt­ka. The sec­tors that use 3D print­ing (i.e., addi­tive man­u­fac­tur­ing) most are main­ly the man­u­fac­tur­ing and trans­porta­tion indus­tries, aero­space and motorised sports. These use 3D print­ers to make machines, robot parts, spare parts, machin­ery, casts, mod­els, etc. The most fre­quent­ly used mate­ri­als are still plas­tic poly­mers in dif­fer­ent for­mats (pow­der, thread, etc.). Only a small part of the mate­ri­als used are metal­lic, ceram­ic or oth­er types.

    In the auto­mo­tive indus­try, addi­tive man­u­fac­tur­ing was first used a way to make pro­to­types, but today it is also used to make mechan­i­cal parts as well as ele­ments of design (car body, spoil­er, etc.). For instance, car man­u­fac­tur­ers like Hon­da have already built vehi­cles com­plete­ly print­ed in 3D, although they are not yet marketed.

    The aca­d­e­m­ic world is also increas­ing­ly turn­ing to addi­tive man­u­fac­tur­ing to sup­port research. Many projects use exper­i­men­tal pro­to­types made with 3D print­ing tech­nol­o­gy. To this end, some lab­o­ra­to­ries or research insti­tu­tions have equipped them­selves with their own print­ers, or even Fab Labs (fab­ri­ca­tion lab­o­ra­to­ry) like those, for exam­ple, of the Insti­tut Pas­teur (FLIP) or the Insti­tut Poly­tech­nique de Paris.

    What are the main advan­tages of addi­tive man­u­fac­tur­ing in your field?

    Nowa­days, metal­lic addi­tive fab­ri­ca­tion makes it pos­si­ble to cre­ate com­po­nents with com­plex geom­e­try. These would be impos­si­ble to make by using con­ven­tion­al meth­ods. For exam­ple, very small details would break dur­ing demould­ing in a clas­sic foundry. In some cas­es, weld­ing can be used to repair parts, but this tech­nique is very sen­si­tive to ambi­ent con­di­tions (air tem­per­a­ture, humid­i­ty) and very dif­fi­cult to auto­mate. You need many spe­cialised oper­a­tors, who require much long train­ing. Addi­tive man­u­fac­tur­ing thus makes it pos­si­ble, to some extent, to make up for the lack of spe­cialised workers.

    What does your research on metal­lic 3D print­ing con­sist of? 

    Our objec­tive is to study metal­lic mate­ri­als pro­duced by addi­tive man­u­fac­tur­ing. We use a spray­ing tech­nique based on metal­lic pow­der called “Direct­ed Ener­gy Depo­si­tion” to make our own mate­ri­als. Their qual­i­ty depends on sev­er­al para­me­ters: pow­der com­po­si­tion, pow­er and speed of the machine. We then observe the effects of the vary­ing these para­me­ters on the microstruc­tures of the mate­r­i­al. Final­ly, we test the resis­tance of this new metal­lic mate­r­i­al to mechan­i­cal stress. For instance, we eval­u­ate the strain pro­duced by trac­tion, or mea­sure the effects of heat treatment.

    In our lab­o­ra­to­ry, we con­duct tests on com­plex struc­tures clos­er to the geom­e­try of indus­tri­al parts, while stan­dard tests use a sim­pler geom­e­try (plates, cylin­ders). Our research on metal­lic mate­ri­als tries to meet the demands and needs of indus­tri­al part­ners. For exam­ple, they can ask us to devel­op a mate­r­i­al in com­pli­ance with deter­mined char­ac­ter­is­tics for a spe­cif­ic use. We also lead research stud­ies on poly­mers in col­lab­o­ra­tion with chemists from the CNRS.

    In what fields are your stud­ies applied? And who are the final users of these materials?

    One of the most promis­ing areas of inves­ti­ga­tion is the use of these process­es to repair dam­aged struc­tures. To devel­op appli­ca­tions for these metal­lic mate­ri­als, we work with the ener­gy, trans­porta­tion and aero­nau­tic sec­tors. For exam­ple, our part­ners EDF and SNCF use parts with very large dimen­sions. Their design some­times dates back to near­ly twen­ty years ago and, as such, they are very dif­fi­cult to replace since they are not pro­duced any­more. Hence the need to find prac­ti­cal and cost-effec­tive solu­tions to repair them.