Additive Manufacturing: What do you require to qualify components?
Interview with Kim Färnlund, Materials Lab Team Lead at AMEXCI
One question that we receive quite often from our customers is related to component qualification for Additive Manufacturing. Component qualification is an important topic in the AM world, as many professionals in this field would like to have a defined process for AM component qualification. Therefore, we would like to present you with a personal perspective on this matter. In this article, we talked to our Materials Lab Team Lead, Kim Färnlund, about how he views this topic.
Kim, thank you for taking the time and wanting to be part of this interview. The main topic of discussion for today, that we get asked many times by our customers, is “What do I require to qualify my component?”
This is a very interesting question that, indeed, gets asked a lot. I believe there are several different ways of looking at it. From my perspective and experience, it really should not be much different from how the internal procedures look for conventionally manufactured components in each respective company. Of course, this is a half-truth, but in essence, that is it.
So, in essence, what you are pointing out is that AM does not have any other particular qualification procedures compared to conventional manufacturing?
There are, of course, special considerations that must be made. The complex geometries make it difficult to apply some conventional technologies, such as certain non-destructive testing methods, due to the hard to reach as-manufactured surfaces. However, the trust in the material and technology is something we have to build as we would for any new material and technology.
That is true, AM is still undergoing a lot of research and development. Nevertheless, could you mention some of the first steps to keep in mind when qualifying a component produced through additive manufacturing?
I think it is easy to forget, and important to keep in mind, that the qualification process is meant to do one thing: to provide enough confidence in the part to be able to use it without fear of it causing or facilitating a failure, be it in terms of a breakdown, or not fulfilling its promised potential. The second thing is that AM is new, but it is not necessarily different. Anyone who is thinking in terms of qualifying an AM component has most likely qualified hundreds or thousands of conventional components in the past and has the confidence to use these with little fear of failure. This confidence has come from the experience built up over many years.
I agree, it takes time to build understanding of new technologies. However, could you provide an example of a similar qualification procedure for a conventional manufactured part and an AM part?
I think that if we ignore the terms “AM” and “Conventional”, the process is mostly the same. The missing components in terms of material data, design, manufacturing site, etc, have to be identified and tackled. Sometimes when the words “AM” are introduced into the discussion, an insecurity arises, largely an unwarranted one.
Also, you said that it is a half-truth that AM can be treated the same as conventional technologies, what do you mean by that?
I’ve had the most success when I was able to adapt the existing procedures for qualification of components. Most companies have them, and often departments, experts, and part owners (the governing instances), that in the end will make the decision of using the part or not. If there is an existing procedure for qualification internally, adapt that to the largest extent as possible. Do not try and re-invent the wheel more than necessary, and instead do what the decision-making instances are familiar with. Sounds easy, but here comes the caveat. It often takes time and money, something the AM industry hasn’t been blessed with an abundance of, as it is moving in such a fast pace. Herein lies the half-truth that I was mentioning before. The decision is made on the available data, both in terms of experience and material data. In AM, we are far away from the plethora of data and experience available for the conventional materials. Therefore, we cannot be expected to provide the same information for AM materials in the same timeframe. It is important to focus on key properties of the part for which data is needed to ensure that the quality is sufficient for the task. The amount and nature of this data is of course very much dependent on the specific components. In order to manage expectations, it is critical, early in the projects, to involve whomever is to make a decision on the project, reach a consensus of what is needed for the qualification of the part, and reduce the scope to something manageable that can still be accepted.
You are mentioning “key properties” that are needed for ensuring the quality of the part. I know you said it is dependent on the specific component, however could you give few examples of what this data includes?
Certainly! With key properties, I mean data that describes the key failure modes or key requirements of any component, I.e., the critical data, which I guess does not have to be mechanical or physical data. Of course, it would be great to have extensive testing and understanding of everything related to the material, but the priority is to investigate the specific load cases of the specific part to get it out on the market. The data generated from each project will be like a piece of a puzzle. With enough projects, the puzzle will be completed, and the full data bank will slowly be filled.
Another important topic here is time. From your experience, could you tell us about how we can speed up the process?
Target the low hanging fruit, the projects that do not require much in terms of special data for the qualification process, and build that puzzle of confidence and experience, while also working on the long-term projects. Also, look at alternative ways of gaining experience and confidence. For example, looking at ways of testing the actual part, rather than extrapolating data from test specimen. Oh, and start mechanical testing early, there is only so much of the testing that can be accelerated, every sample takes time.
Finally, could you mention some of the things that you see necessary for the future of component qualification?
We are still early in the process of adopting this technology, many things are changing, and it is something to be aware of when getting into this industry. Due diligence is necessary. It will provide the foundation to the work for years to come and postponing it will only result in future delays. The more information is gathered, saved, and evaluated early; the more is gained long term.
About Kim Färnlund
Kim is working as the materials lab team lead at AMEXCI with close to a decade of experience in the field, focusing on metal materials testing and analysis, process parameter development, material and component qualification, and health and safety topics related to AM.
