A new application for one form of 3D printing has been identified by researchers in Massachusetts.
Researchers from the University of Massachusetts Amherst and MIT Department of Engineering wanted to see whether a road bridge could be repaired in place.
The project combines a technology with a growing need.
The technology involved is called “cold spray” additive manufacturing. This process sprays metal particles at high speeds towards a metal target. The kinetic energy pushes the molecules so tightly upon impact that they naturally bond together. Repeated applications produce layers of metal. There is no heat involved, so it’s called a “cold” process.
The cold spray process can be used to build entire metal objects by repeated layering. This is precisely what is done by Spee3D, whose technology can accelerate particles to supersonic speeds.
The need in this case is aging bridges. In the US, many bridges were built decades ago, and they are now reaching retirement ages. Corrosion of metal always occurs, and this is generally what causes bridges and other metal structures to eventually require repairs or replacement.
Bridge repair and replacement is a well-known process, but the issue isn’t the process, it’s the scale. According to the University of Massachusetts, the bill for the US to repair its aging bridges exceeds US$190B.
If only there were a way to do this in a less expensive manner.
There could be! The researchers devised an experiment to “bulk up” the corroded metal beams on a sample bridge using cold spray technology. This allowed them to repair the bridge without having to take it apart, as would be required using traditional repair methods.
The report even suggests that if this approach is successful, it might even enable bridge repairs to take place while traffic proceeds on top of the bridge.
Another part of the project was to determine what portions of a bridge actually need repair, and to what degree. The researchers used a LIDAR system to identify the damaged areas. They explain:
“Part of this work has been developing 3D LiDAR scanning methods to replace time-consuming, subjective visual assessments. This enables researchers to precisely identify corrosion, develop a digital repair plan, and deposit the material only where necessary.”
This approach will not replace bridges, but would certainly add more operational years to a bridge that otherwise would have to be replaced at great expense.
Via University of Massachusetts (Hat tip to Benjamin)
