Metrology & Maintenance

Quality for metrology and maintenance aspects related to AM manufactured end product are discussed. This chapter summarized the full ManSYS report on Maintenance and Metrology, which can be downloaded HERE.

amvaluechainmetrologymaintenance Applications: regulations and requirements Design Machine Material Process Post-processing Quality Management System for AM

Keywords: Metrology, Destructive Testing, Non-destructive testing, 3D scanning, standards, maintenance

Content

  1. Non-destructive testing
  2. 3D scanning and inspection
  3. Standards
  4. Maintenance

1. Non-destructive testing

In order to validate the part quality the application and process specific requirements need to be measured. ISO 17269-3 provides an initial guideline to classify which quality aspects need to be checked.

In general, the two main groups of testing include;

  • Destructive Testing; Methods which limit or remove part functionality
  • Non Destructive Testing; Method which do not interfere with part functionality

2. 3D scanning and inspection

3D scanning and inspection is the final step of the post processing activities. For fulfilling QA/QC requirements, it is important to check if the component has been built accurately within the acceptable limit.

We adress the following article for more information about 3D scanning and inspection:

Review of in-situ process monitoring and in-situ metrology for metal additive manufacturing

3. Standards

Concerning standards specific for metrology and maintenance, it is important to mention the development by ISO, CEN and ASTM, as described in chapter Applications.

In particular ASTM subcommittee F4.2.01 on Test Methods is working developing particular standards for additive manufacturing testing methods. Currently there are three active standards:

  • F2971-13 Standard Practice for Reporting Data for Test Specimens Prepared by Additive Manufacturing.
  • F3122-14 Standard Guided for Evaluating Mechanical Properties of Metal Materials Made via Additive Manufacturing Processes.
  • ISO/ASTM2921-13 Standard Terminology for Additive Manufacturing-Coordinate Systems and Tests Methodologies.

Some additional standards are in the status “working progress” to be proposed as new standards.

Moreover, there are some standards developed for particular materials. These standards define all properties that shall be tested to obtain a quality part made by a particular additive manufacturing technology. For example these are the active standards developed by the subcommittee F42.05 on Materials and Processes:

  • F2924-14 Standard Specification for Additive Manufacturing Titanium-6 Aluminum-4 Vanadium with Powder Bed Fusion
  • F3001-14 Standard Specification for Additive Manufacturing Titanium-6 Aluminum-4 Vanadium ELI (Extra Low Interstitial) with Powder Bed Fusion

More standards can are referred to in the full report on metrology and maintenance.

4. Maintenance

Maintenance concerns the tasks related to maintaining the functionality of a part. This includes the status of the part, as well as potential replacement of repair of the part. While maintenance for AM parts is largely similar to conventional production technologies, there a number of quality aspects which need to be considered. The specific quality aspects related to maintenance of AM parts are due to specific AM characteristics, namely;

  • New technology with limited standards
  • Design freedom leading to complex shapes

A solution to monitor the status of a part is a novel technology active structural health monitoring. Here, passive or active system are integrated into the part design to monitor the structural health of the part. Refer to;

Brackett, D., Panesar, A., Ashcroft, I., Wildman, R., & Hague, R. (2013). An optimization based design framework for multi-functional 3D printing. In Solid Freeform Fabrication (pp. 592–605). Austin, Texas.

De Baere, D., Strantza, M., Hinderdael, M., Devesse, W., & Guilaumme, P. (2014). Structural Health Monitoring Systems. In European Workshop on Structural Health Monitoring (pp. 355–362). Nantes, France.