The following is an excerpt from TCT Magazine. The article can be read in its entirety on the TCT Website.
“Cast metal has been widely used in architecture – for facades, bridges, beams, columns and connections. An historical example is the exposed cast-iron arches and columns in the Sainte-Geneviève Library France built by architect Henri Labrouste.
“Today, additive manufacturing (AM) of metal can bypass mould making and offers the ability to produce customised lightweight parts with complex geometry without moulds. Multiple technologies of metal 3D printing exist. However, each have major shortcomings for the application in architecture, where large-scale parts with detailed surfaces need to be produced.
“One of the most common methods is powder bed fusion (e.g. SLM, EBM, and DMLS), which is commonly used for manufacturing small, low volume, complex metal parts. Major drawbacks of employing this technology for the building industry are the small build volumes, long print times and the limited available metal materials that can be printed. Printing methods for larger dimensions, such as robotic metal arc welding-based AM — where stainless-steel rods are printed through welding layer by layer — have recently developed. However, this technique is still limited in printable forms and requires expensive post-processing to reach a high-quality surface finish.
“To overcome these challenges, in our research at DBT, we employ AM to 3D print the sand-moulds for metal casting rather than 3D printing the metal part directly. We do this to benefit from the geometric freedom offered by 3D printing and the flexibility of metal casting. When combining 3D printed sand-moulds with metal casting, we can efficiently create large bespoke elements without being limited to specific metals or alloys – we can cast practically any kind of metal.”