Strength and durability are vital for airliners, cargo ships, nuclear power reactors, and other critical technology. As a result, many are made of a tremendously strong and corrosion-resistant alloy known as 17-4 precipitation hardening (PH) stainless steel. For the first time, 17-4 PH steel may be regularly 3D-printed while preserving its advantageous properties.
The National Institute of Standards and Technology (NIST), the University of Wisconsin-Madison, and Argonne National Laboratory collaborated to identify certain 17-4 steel compositions that, when printed, match the attributes of the traditionally made version.
The new findings might help 17-4 PH component manufacturers employ 3D printing to reduce costs and boost manufacturing flexibility.
Because the material warms and cools so quickly during 3D printing, the arrangement of the atoms within the material, or crystal structure, alters fast and is difficult to pin down.
Researchers have battled for years to 3D-print 17-4 PH without understanding what happens to the crystal structure of steel when it is printed, since the crystal structure must be just perfect — a form called martensite — for the material to display its highly sought-after qualities.
The new study’s authors discovered the perfect technique for comprehending this process in synchrotron X-ray diffraction, or XRD. They used this to map out how the crystal structure altered throughout the course of a print, indicating how some aspects they had control over such as the composition of the powdered metal — influenced the outcome.
With a detailed image of the structural dynamics during printing as a guide, the authors were able to fine-tune the steel’s makeup to identify a set of compositions including just iron, nickel, copper, niobium, and chromium that resulted in totally martensitic 17-4 PH steel.
The new research might have an impact beyond 17-4 PH steel. The XRD-based technique might not only be used to improve other alloys for 3D printing, but the information it uncovers could also be beneficial for developing and validating computer models that anticipate the quality of printed objects.
Reference- Journal Additive Manufacturing, Interesting Engineering, Popular Mechanics, Clean Technica