Powder Pioneer: Rachel Riendeau, quality leader, AP&CNovember 12, 2020
How powder certification ensures high-quality additively manufactured parts
Metal powders used in additive manufacturing are not subjected to the same certifications as finished end-use additively manufacturing parts. So, other approaches must be taken to ensure that they are of a high quality.
While organizations can have external quality system certifications, either general (ISO9001) or for specific application areas, such as medical devices (ISO13485) or aerospace (AS9100), these tend to be focused on the complete management systems in place, rather than the powder itself.
The best way to ensure that your powder is suited for your needs is through internal certifications that detail exactly what you’re getting, including the specific properties of the powder.
Every organization’s needs and applications are different, but when you buy powders from AP&C, a GE Additive company, each product comes with a complete internal certification which ensures that the powder is of a high quality and will meet those specific requirements.
Certification is only possible thanks to a multi-disciplinary effort and rigorous testing at all stages of the production chain—from the raw material to the finished powder.
While many know about third party certifications, we realize that not everyone is aware of what an internal material certification is, so we’ve outlined some of the key steps in the AP&C certification process and what it means when a product has a powder certification.
The Importance of Collaboration
The collaboration between supplier and customer is a crucial part of ensuring that the certification is right, because this is the stage when key parameters, needs, and material properties are defined.
If the scope of the material is wrong from the outset, then regardless of how much the certification fits this scope, it might not be right for the intended application. So, an effective dialogue before any production work begins is key to ensuring that a customer gets the best material for their application.
We realize that everyone is at different stages when it comes to powder knowledge, from those who know exactly what they want to those who still need a lot of guidance. At this guidance stage, expectations need to be managed as certain requirements will not be feasible, optimal, or will be too restrictive with the systems in place. This is where strong internal collaboration helps external collaboration, as expertise from many areas within our business come together to find an optimal solution, and this in turn helps to define the key parameters, needs, and material properties for each customer and find the most optimal solution for their needs.
Collaboration at this stage is not only crucial to ensuring that the finished product has the desired properties, it also enables the powder user to understand what risks are present and understand whether these risks are justified, or whether other approaches should be sought. On the powder side, these discussions can highlight how the requirements for each powder and application are different, arming the user with extra knowledge going forward.
Across GE Additive, these discussions are vital for helping our customers. Each conversation brings something new and that helps us to better tackle future challenges and requirements. In some cases, interesting solutions might be developed, which in turn enables us to look at our own processes and see where we can improve internally.
How Culture and Certifications Go Together
That efficient internal collaboration and crosstalk between the different experts and groups within the business enables us to best serve the needs of customers and our external collaboration partners. However, these external collaborations would not be as effective if it wasn’t for the quality-focused culture within AP&C and across GE Additive.
This internal culture of ensuring quality at all stages of production has not only enabled AP&C to obtain third party certifications for aerospace and medical device applications, it has helped to refine the internal certification process as well. As a business we have always strived towards quality and this is what enables us to work and communicate effectively with customers to produce powders that meet their exact needs.
So, while it may not be obvious, our internal culture and focus on quality is in many ways the driving force behind AP&C’s success when it comes to certifications. Obtaining external certifications and producing internal certifications for our powders both require a lot of time, effort and discipline from multiple teams working harmoniously. These certifications are only possible thanks to the ingrained quality-focused ethic throughout the organization.
The AP&C Material Certification Process
We’ve discussed how collaborating with the customer and the internal culture are key to producing accurate material certifications, but it’s important to understand what goes into a certification and why it’s useful to have a powder supplier that provides material certification. We’ve mentioned that several different teams are involved with the certification process and this ensures that every aspect of the process has been scrutinized and analyzed by a relevant expert.
The certification process starts during the initial conversation about powder requirements. This stage is crucial as it defines the parameters, processes and general working methods going forward based on the requirements of each customer. Without this stage, the rest of the processes could not be analyzed, refined or appropriately determined to produce the powder, and there would be no need for a tailored certification.
Once the characteristics of the powder have been defined, the raw materials used to make the powder are controlled to the highest standards and all suppliers must go through a qualification process, as well as periodic performance evaluations and regular surveillance. The materials also go through extensive testing before use in our systems.
Again, efficient communication and collaboration at this stage ensures that the highest quality raw materials are used for our powder products.
During the powder manufacturing stages, there are several controls, both on the equipment and the processes, as well as on the powder itself. This ranges from process validation methods to controlling the processes during the advanced plasma atomization process—the method which creates the powder—to having a standard change management process dialogue in place, in case there are any changes/issues throughout production, which minimizes overall risk.
Each type of material has its own dedicated closed system equipment so there is no risk of cross-contamination. All these processes are controlled via workstation verification controls that ensures a high-quality environment from workstation to workstation.
The final stage that leads to producing the material certification is the analysis of the powder itself once it has completed all steps of the manufacturing process, from the atomization to classification to final blending. These tests range from visual tests—to ensure that the powder sphericity is right and is free of contaminants—to chemical and physical tests which determine the flowability and particle size properties, among others, of the powder.
Additional tests are sometimes performed if the intended application/the customer requires it, but this is always set out in the initial discussion stages.
For each powder produced and tested, a material certificate is then produced which shows all the testing results against the customer’s requirements. This makes it easy for customers, to have all the information in one place to make sure the product is compliant to their requirements—and this reinforces why the initial discussion stage is crucial. This process certifies that the product has been manufactured to your specific requirements.
What Should Powder Users be Thinking About?
We realize that not everyone will understand powder straight away, nor will they know exactly what they want or need. Therefore, we work to understand your requirements, guide you throughout the entire process, and provide you with a certification that details all the relevant properties of your powder for your intended application.
However, while we do a lot of the hard work, there are a few things to consider as you evaluate and decide on what powder might be best for you;
- Powder users should also think about whether they need a fine powder, as coarser powders can still bring similar benefits than finer ones (if processed in specific ways, and depending of end-applications) but at a much lower cost (not only powder cost, but also printing cost).
- As a potential powder user, you should also be assessing the different risks of your application, as this will determine what properties the powder will require. You will also need to make sure that your requirements are not too restrictive when they don’t have to be. If you’re not sure if this is the case or not, then our technical experts can guide you through this and assess any potential impacts and risks.
- The benefit of using powder is that you use less material for your parts, but what would you like to do with any leftover powder once you’ve used what you need, or if you leave it too long and it is not as usable as when you first received it? One potential option would be to send it back to us for reconditioning, where the powder is mixed with new powder to make it functional again.
This is all food for thought, as you think about your powder needs. To discuss which specific powder might be best for your application, or for like more information on our certification process, please get in touch.