Matlack lab now houses metal 3D printer
Binder jet printing is a form of additive manufacturing (3D printing) which involves laying a liquid binder chemical onto fine metal powder (stainless steel) layer by layer, similarly to an ink printer. In contrast to laser bed fusion printers, which melt the powder locally, the metal powder is held together by the binder chemical. The excess powder is then removed and the part is placed in a furnace to be heated uniformly. To account for pores that may appear during the binder jet printing process, the parts are also infused with bronze.
Now, Professor Katie Matlack’s Wave Propagation and Metamaterials (WPM) Laboratory owns and operates one of these innovative machines. Her ExOne Innovent binder jet printer is located in the basement of the Mechanical Engineering Laboratory (MEL). Matlack’s graduate student, Betsy Smith, works in the WPM Lab and has been printing samples for a variety of the group’s research projects since she came to Illinois in the fall of 2018.
The WPM lab studies phononic materials and mechanical metamaterials, which often have intricate geometries that can only be fabricated using additive manufacturing. Previously, they researched polymer-based 3D printing to create their samples. However, metal structures are more representative of structural and load-bearing applications, and could enable new applications of these engineered materials.
Binder jet printing has grown in popularity in industry as it is more cost-effective than many other metal printing approaches (such as laser-based systems), and by heating the part all at once, binder jet samples are more homogenous than locally sintered printed parts.
“The facility should enable new research directions related to materials, advanced manufacturing, mechanics, and heat transfer, among many others. The WPM Lab will use the printer to fabricate metamaterials, with properties such as frequency filtering and wave guiding. Thermally tunable metamaterials is another possible field of study, as well as nondestructive evaluation of 3D printed parts,” Smith said.
The printer in Matlack’s lab is now available for department use and will be run by a staffed operator. A description of the process and the part request form can be found on the WPM lab website.