In this installment of AM Hub, Alex Bast, Heat Treatment Process Engineer at Burloak, shares why heat treatment is an important part of an integrated AM solution.
What is heat treatment and what benefits does it drive?
Many customers are looking for their material to have specific properties that will allow parts to perform optimally in their operational environment. Heat treatment allows us to achieve the final desired properties of a selected material or part. Requested properties are usually application-specific and defined by our OEM customers in drawings or specifications. These requirements are usually proven through various testing and inspection methods such as hardness, microstructure analysis, and tensile and fatigue testing to name a few.
How is heat treatment conducted?
While heat treating for conventional methods of manufacturing (castings, forgings, etc.) has been well established over many years, these methods may no longer be entirely relevant for additive manufacturing. Burloak Technologies strives to be on the forefront of the development of new techniques and operational parameters to meet and outperform customer requirements and expectations.
We currently offer three types of heat treatment – vacuum heat treatment; aluminum solution anneal, quenching and aging; and hot isostatic pressing (HIP). Having these technologies in-house for post processing enables us to offer a complete AM solution under one roof.
Vacuum heat treatment is used for materials that are sensitive to atmospheric contamination. Some materials, such as titanium, Inconel and steels are prone to reactions at elevated temperatures which negatively impacts their properties. The vacuum furnace at Burloak Technologies can run at very low levels of vacuum for high cleanliness. The furnace can also operate with clean inert gases of high purity to prevent the de-alloying of certain materials.
Aluminium solution anneal, quenching and aging treatments are used to achieve a long list of final material properties. Using state-of-the-art automation, Burloak Technologies is capable of achieving these properties in a very consistent and repeatable manner.
Lastly, hot isostatic pressing – affectionately known as HIP – is used to reduce porosity of parts and consolidate powder metallurgy materials. It works with all types of metal alloys including titanium, steel, aluminum, and super alloys. An industrial sized HIP is a rare and exciting piece of equipment. It was a great experience to build and tailor this impressive process to ensure we drive the most benefits for our customers.
How do you determine which parts need heat treatment during post-processing?
The approach taken in post-processing is directly aligned to the properties our customers require in their parts. Every industry, customer, and application can be different. We need a clear understanding of the customer’s expectations and specific requirements, including any industry standards that must be adhered to.
In addition, deciding to conduct heat treatment typically depends on a part’s intended use. For example, heat treatment in the aerospace industry is very controlled and heavily regulated. We are required to adhere to many industry standards and customer-specific standards. So while a small metal clip for use in a consumer product may be satisfactory without heat treatment, a titanium component going into a passenger aircraft must comply with strict requirements and therefore needs heat treatment to ensure specific levels of porosity, tensile strength, material grain size, and the ability to withstand harsh conditions.
Once we understand the specifications, we can then develop the exact solution, or “recipe” to achieve the customer’s goals.
I understand Burloak recently achieved NADCAP certification for its heat treatment solutions. Why is NADCAP certification important for this aspect of AM?
NADCAP certification for heat treatment is critically important for an AM company serving the space and aviation industries and enables us to offer a fully integrated solution for all types of customers.
For Burloak, NADCAP certification means that we can now conduct heat treatment for critical components in-house. As you can imagine, this reduces turnaround time for our customers and gives us more control over the entire end-to-end process. In addition, by having this capability in-house, we are even more confident in the unique processes we develop because we are building and testing them on the very machines we use to treat customers’ parts.
Lastly, this certification signals to OEMs in highly regulated sectors that they can trust Burloak to provide state-of-the-art heat treatment for their mission-critical parts. This creates trust in our team and our processes and demonstrates that we are investing in our customers’ success.