Invention Reference Number
For additive manufacturing of large-scale parts, significant distortion can result from residual stresses during deposition and cooling. This can result in part scraps if the final part geometry is not contained in the additively manufactured preform. This technology is a method for monitoring additive manufacturing part geometric accuracy through intermittent machining, using spindle power to detect the geometry during machining.
Description
Intermittent machining in a hybrid additive and subtractive system during the additive manufacturing process solves the problem of distortion and scrapping large parts that are being machined. The intermittent machining is monitored using a power transducer to measure the cutting power. The cutting power can then be used to detect when the tool is in-cut in a given tool-path, giving the machined part geometry. Existing solutions for additive part geometric accuracy monitoring use sensors, cameras, optical scanning, and inspection probes, but these are cost prohibitive and time-consuming to implement. Also, part geometric accuracy monitoring using optical scanning tools or an inspection probe requires the part to be cooled to ambient temperature, which can take several hours. Based on the final additive preform geometry, intermittent machining steps are programmed to machine a layer or multiple layers of the deposited part at the selected machining parameters. The cutting power is measured in the intermittent machining steps. By comparing the measured power to the spindle idle power and the expected power, the tool position when the tool enters and exits the cut is determined. This can be done for multiple passes to create a geometric shape of the additive preform. The geometric accuracy is given by the difference between the detected shape and the expected shape.
Benefits
- Defines geometric accuracy monitoring of components
- Low cost
- Fast and efficient
- Improved performance
- Improved quality, reduced scrap
- Increased productivity
- Single sensor in control cabinet
Applications and Industries
- Machine tool OEMs
- Process monitoring OEMs
Contact
To learn more about this technology, email partnerships@ornl.gov or call 865-574-1051.
