As a provider of automation equipment and software, our company is immersed in this ongoing, revolutionary, data-driven ride, and we’re anticipating a new trend: our customers are not just automating their traditional subtractive methods, they are also looking to automate their hybrid manufacturing processes (combined additive and subtractive processes) to take advantage of the main benefit of any flexible manufacturing system (FMS): establishing a reliable, consistent process and production flow that can operate 24/7.
The aerospace industry will be among the first to adopt the hybrid manufacturing FMS. The medical industry is surely close behind as many of its applications are well suited to a high production hybrid process. A hybrid manufacturing FMS configuration will have similarities and differences with a conventional subtractive machining FMS. Commonalities include the digital aspects—such as part and fixture file preparation, tie-in with an ERP system for scheduling prioritization and material inventory, and connection with the FMS controller that directs selecting, monitoring, analyzing and changing the conditions.
The differences in a hybrid FMS will lie mainly in the work handling aspects. For example, there likely won’t be a pallet stacker with a crane as in subtractive cells. The hybrid system level handling device is typically an industrial robot. Robots with dedicated fingers or grippers will move first the build plate and after part removal the individual part from machine to machine.
We foresee processes that will be necessary for a customer to include in future hybrid FMS applications and others that will be interesting and potentially beneficial for the customer to integrate. It all depends on the family of applications and the motivation of the company to become as automated as possible, often citing the great unknown—availability of skilled people in the future—as one of the leading drivers to automate.
The necessary functions would include all of the part data preparation as mentioned above; unpacking (removing the part from the powder plus powder recycling); support structure and build plate removal; heat treatment/stress relieving; and surface finishing, such as shot peening.
If the part is a critical one, the optional functions than can be integrated could include all the quality assurance activities for the powder material, comprising powder selection, drying, screening, filling the machine’s powder tank and powder disposal. Primary quality assurance actions will be done on the completed part, which is then ready to be transported to assembly (which can also be automated downstream).
Hybrid Application is Ready Now
Aerospace turbine blades are a key hybrid application ready for automation now. The blade is manufactured layer by layer using direct metal laser sintering. The powder is comprised of Inconel, the nickel chromium-based superalloy used in aircraft engines. In this case, the workpiece is transported on a platform from the additive machine to subsequent stations. The print support structures are automatically cut away and the turbine blade is unpacked and detached from the build platform by a robot.
The detached blade gets its secondary operations processed automatically using a variety of finishing tools. Even the robot’s fingers are 3D printed using an aluminum-based powder, providing the optimal weight-to-stiffness ratio. The 3D printed finger inserts and the workpiece fixture are matched with the complex “fir-tree” geometry precisely for a solid and reliable grip.
We see full automation of the hybrid process on the horizon. The implementation of an FMS for hybrid manufacturing offers the benefits of shorter lead times, no sophisticated tooling required and a highly stable, consistent production flow—24/7.
Originally published in Manufacturing Engineering – March 2019 Automation Issue