Are your additive manufacturing powders usable?

Parts produced by additive manufacturing can be found in an increasing number of sectors where quality criteria are extremely strict, such as the aeronautical field and medicine. For the manufacturers producing these parts, command is essential, not only of their production tool parameters, but also of the quality of the raw materials they comprise. Sirris helps those manufacturers to implement robust quality assurance and control systems.

The powders used in additive processes can alter due to a number of factors. Simple exposure to air or heat can suffice to change their properties. Their receipt, storage, transport in a production unit and their implementation within the first manufacturing cycle are all critical steps likely to impact their characteristics.

Recovery of excess powder aimed for reinjection into subsequent production cycles brings added complexity: raw materials are generally composed, either of a blend of new and recycled powders, or are taken from a unique batch that has been recycled several times.

For all manufacturers, the same recurrent and critical question remains, ‘is my powder still usable for the quality criteria I hope to meet?’

Many questions remain to be answered

Quality assurance relies on rigorous command of the essential characteristics of AM powders, whether they are sourced from a supplier or from the company’s own recycling unit.

This implies answering a number of questions, upstream of the production process. What criteria determine final product quality? What quality controls need to be conducted? What are the acceptable deviations?  But also - how to take a control sample that is representative, since each particle is not subjected in the same way to heat or damp for example? And more generally, how to handle powders (upon receipt of delivery, during storage and transport), to avoid significant alterations? How to guarantee raw material traceability over successive blends and recycling operations? Etc.

By gaining full command of all the above, you provide yourself the opportunity to diversify procurement sources and to guarantee a robust overall process - which is a requirement in the aeronautical field in particular.

Good practices and acceptance criteria

To help businesses establish a robust quality assurance system for their additive manufacturing processes, Sirris can intervene at several levels. One of them consists in establishing acceptance criteria that are adapted to suit the additive manufacturing field. What necessary and sufficient constraints should be applied to each type of powder, to ensure a quality finished product?

Sirris also studies good handling practices that should enable the initial powder characteristics to be preserved. Hence, we in a far better position to understand the consequences of powder exposure to damp during handling operations.

Thanks to Sirris, command of the impact of the AM process itself on recycled powder quality is also improved. For example, we can improve our understanding of how argon blowing - used to cool the fusion zone - can alter powder characteristics.

A share of these results was presented at the Euro PM2019 congress held in Maastricht.

Discover good practices for handling AM powers with our experts

Join us on 7 November 2019, to meet with them and to discover, among others:

  • our AM raw material characterisation laboratory
  • our latest results regarding good practices in powder handling
  • advances in the field of powder quality monitoring thanks to embedded systems.

This article is part of our ‘4.0 made real by Sirris’ campaign, illustrating the feasibility of 4.0 technology in industry. Want to know more? Visit our 4.0 Made Real page or LinkedIn page!