Udimet 520 Nickel Alloy Powder: 3D Printed Parts

Author:Enrique J. Lavernia

Enrique J. Lavernia is a renowned materials scientist and Professor at Texas A&M University, recognized for his pioneering contributions to additive manufacturing. His research focuses on metallic powders, including their atomization, characteristics, and impact on part quality, as well as the microstructural evolution and mechanical performance of advanced alloys during additive processes.

He has advanced the understanding and application of complex materials such as aluminum alloys and high-entropy alloys in AM, and co-authored authoritative works on metallic powders for additive manufacturing, significantly influencing both scientific research and industrial practice.

Udimet 520 Nickel-Based Alloy Powder: A New Chapter In Additive Manufacturing For High-Temperature ‘Veterans’

A. Material composition and metallurgical characteristics

You know, I often compare Udimet 520 to a “well-orchestrated team”. Its outstanding performance is by no means the result of a single element, but the result of the perfect cooperation of all “players” in their respective duties.

Nickel as the matrix, that is no doubt the “captain”, but really give it super combat effectiveness, is those alloy elements:

• Chromium (Cr): This is simply the “anti-corrosion coating” and “anti-oxidation armor” of the material “. Especially in those hundreds of thousands of degrees of high temperature environment, without it, the material may have been unable to carry. My personal experience is that high chromium content is critical to the surface integrity of our prints.
• Cobalt (Co): I call it “stabilizer” and “booster”. It can make the austenitic matrix stable at high temperatures, and at the same time, through solid solution strengthening, the material can maintain sufficient strength even in the red hot state.
• Molybdenum (Mo) and tungsten (W): These are typical “muscle enhancers”. They are like “rivets” embedded in the lattice, effectively hindering the movement of dislocations. Imagine you want to push a stone, but it’s held in place by a million small nails, so it’s hard to push it. That’s how they fight creep.
• Titanium (Ti) and aluminum (Al): This combination is simply the “secret weapon” of the Udimet 520 “! The gamma prime (γ’) phase-Ni3(Ti,Al)-formed by them is the “nuclear power” of the material’s high temperature strength and creep resistance “. These nanoscale γ’ precipitates are evenly dispersed in the nickel matrix, just like adding countless micro-scaffolds to the material, firmly supporting the skeleton of the material.I tell you that in additive manufacturing, how to precisely control the precipitation, size and distribution of the gamma phase is definitely the key challenge that determines the final performance.
• A small amount of carbon (C), boron (B), zirconium (Zr): don’t look at their content is small, but the role should not be underestimated. They are like “glue”, strengthening the grain boundaries and improving the fracture toughness of the material. In 3D printing, the grain boundary is well controlled, and the printed parts are not prone to cracks.

In terms of microstructure, the most classic of the Udimet 520 is the dense γ’ precipitation phase in the γ-austenite matrix. I can see at a glance that the distribution uniformity and size of these γ’ phases are directly related to the “health” of the print “. When our engineers optimize the printing parameters, a large of their energy is to figure out how to control the gamma prime phase through laser energy and scanning strategy to make them grow “just right”.

B. Performance in traditional manufacturing processes

When our 3D printing was not “popular”, Udimet 520 was mainly made by casting and forging these traditional processes. Think about the turbine disks of aero engines and the blades of gas turbines. Those are the “heart” parts that work under extreme temperatures and high stresses. Udimet 520 is their “backbone”.

Its excellent performance in long-term service at 700-800°C and even higher temperatures, including high-temperature tensile strength, creep rupture strength and fatigue performance, has set a very high performance “benchmark” for our additive manufacturing “. My understanding is that if our 3D printed parts can achieve or even surpass the performance of traditional parts in the same environment, that is the real ability and the real advantage of additive manufacturing.

C. Special requirements for powders for additive manufacturing

Well, now let’s talk about the “lifeblood” of additive manufacturing. Udimet 520 to be used for 3D printing. Its powder can’t be used casually. The requirement is really “harsh” and “one in a million”.

Particle size distribution (Particle Size Distribution, PSD): This is the most basic. The powder particles should not be too coarse and the laser is not easy to melt. Nor can it be too fine, the fluidity will be very poor, and it is easy to hug and absorb moisture. I usually choose a very narrow and uniform particle size range, such as the commonly used 15-53 microns, depending on the laser power and powder spreading system of our equipment. In my opinion, a stable particle size distribution is the “first threshold” to print out the high quality piece “.

Spherical (Sphericity): This is so important! The powder particles must be round “small steel balls” so that they can flow and smooth evenly like water when spreading powder. Irregular shape of the powder, will cause the powder layer is not uniform, leaving a gap, directly lead to print holes or defects. Every time I get new powder, I will habitually check their “body shape” under the microscope to see if they are round enough.

Fluidity (Flowability): This is directly related to the smoothness of the printing process. Whether the powder can flow out of the hopper “obediently” and spread evenly on the construction plate depends on its fluidity. We usually use Hall flow meter to measure. Poor fluidity of the powder, print up all kinds of trouble, spread powder uneven, forming interruption, it is a nightmare.

Loosen density (Apparent Density) and tap density (Tap Density): These parameters reflect the “firmness” of the powder packing “. High density powder means that there are more materials in the same volume, which can not only improve the printing efficiency, but also reduce the shrinkage deformation in the sintering process to a certain extent, which is very helpful for controlling the accuracy of parts.

Chemical purity and oxygen content: this is simply a “lifeline in the lifeline”! For Udimet 520 this high-temperature alloy, any tiny impurities, especially oxygen, nitrogen these interstitial elements, may be like “rat shit”, seriously damage the high temperature performance and mechanical properties of the material.

Therefore, I require that the Udimet 520 powder provided by the supplier must be of high purity and ultra-low oxygen content. For each batch of powder received by our laboratory, the first thing is to do a detailed chemical composition analysis, and during storage and use, we will take the most stringent moisture-proof and oxidation-proof measures.

Microstructure uniformity: high-quality powder, not only the particles are better, the chemical composition and microstructure of each particle must also be uniform, and there must be no segregation. In order to ensure that we melt and then solidified out of the material, the performance is stable and reliable.

Application Advantages Of Udimet 520 Powder In Additive Manufacturing

A. High temperature performance and structural integrity

Speaking of Udimet 520, its performance in high temperature environments is simply impressive. We all know that many metal materials will “weak” at high temperatures, but Udimet 520 creep strength, fatigue strength and oxidation resistance to maintain excellent structural integrity even at extremely high temperatures.

This is not a casual remark.

We have almost strict requirements for high temperature resistance of materials in key applications such as aero engine components, gas turbine blades and nuclear reactor components. Udimet 520 is the kind of material that allows you to “rest assured” that it can work stably for a long time under these extreme conditions, which is very important for safety.

B. Design freedom and the realization of complex geometries

One of the most fascinating things about additive manufacturing is its ability to push the limits of traditional manufacturing and achieve complex geometries that were once considered “impossible. When we combine high-performance materials like Udimet 520 with additive manufacturing, this advantage is infinitely magnified.

Imagine that we can design extremely complex cooling channels inside a part, or achieve a more lightweight lattice structure.

This is not only a change in appearance, but also a leap in function. High-performance materials combined with design freedom mean we can make lighter, stronger, and more efficient parts that were previously unimaginable.

C. Material utilization and cost effectiveness

For high-value nickel alloys such as Udimet 520, material utilization has always been an important factor to consider. Traditional subtractive manufacturing, such as milling, generates a large amount of scrap, which undoubtedly increases costs. Additive manufacturing greatly improves material utilization, and its “on-demand manufacturing” feature reduces material waste. For this expensive alloy, the economic benefits are very significant.

Especially in small batch production and prototype manufacturing, the advantages of additive manufacturing combined with Udimet 520 are more obvious. We don’t need to invest heavily in complex molds to produce high-performance customized parts quickly and economically, which is especially important in the current rapid iterative development.

Case Studies & Performance Validation

A. Examples of applications in the field of aerospace

Speaking of Udimet 520, the first thing that comes to mind is definitely aerospace. This alloy is born for high temperature, high pressure environment. Our team has been involved in a project a few years ago, using SLM technology to print turbine blades for aero engines.

As you know, traditional cast or forged turbine blades are always limited in design flexibility and material utilization is not high. “By 3D printing with Udimet 520 powder, we were able to achieve extremely complex internal cooling channel designs that would have been almost impossible with conventional processes.

As a specific example, we have printed new turbine nozzle blades that work in high-temperature and high-pressure gas streams. Through fine topology optimization and internal lattice structure design, we have successfully reduced the weight of the blade by about 15%. At the same time, under simulated conditions, its high temperature creep resistance and thermal fatigue life have shown significant improvement. This is not a small number.

In aero engines, every 1g weight reduction means a huge increase in fuel efficiency. These parts have indeed demonstrated excellent performance after undergoing rigorous non-destructive testing and performance testing. It can be said that 3D printed Udimet 520 components are quietly changing the design and manufacturing pattern of aero engines.

B. Potential Applications in Energy, Healthcare, and Other Fields-My Additive Manufacturing Perspective

As the veteran of additive manufacturing (3D printing) for many years, I have always felt that the potential of Udimet 520 is not limited to aerospace. To be honest, whenever I see the data of this nickel-based superalloy powder, countless “we can print like this and optimize like that” will automatically appear in my mind.

Let’s talk about the energy sector. You see, the core components in gas turbines, such as combustion chamber linings, turbine blades, and certain key structures in nuclear reactors, they are all dancing on the tip of a knife-high temperature, high pressure, and corrosion. Udimet’s 520 high temperature strength and corrosion resistance are simply tailored for these extreme conditions.

More importantly, with 3D printing as a sharp weapon, we can completely liberate design thinking. Any special-shaped cooling channel, dot matrix structure, and complex geometric shapes that were previously unthinkable can now be integrated. This is not only to use kinds of good materials, but also to bring a qualitative leap in the structure and performance of the whole component.

I often discuss with the engineers of the team that if we can use our additive manufacturing process to make the combustion chamber components of the gas turbine lighter, better heat dissipation, and even integrate some innovative microstructures, it will improve the overall energy efficiency., It is absolutely revolutionary. It may also help us achieve greener energy solutions faster.

This is not a simple “change of material”, but a comprehensive innovation from the root, from the design concept to the final product.

As for the medical field, I know that you may immediately think of implants. Well, to be honest, Udimet 520 is currently used directly for human implants. I really can’t guarantee it. After all, biocompatibility is a series of extremely strict testing and verification processes, which can not be crossed casually. However, if we look more relaxed, you will find it in the manufacture of some high-performance medical equipment components, it is too useful!

For example, those parts of surgical instruments that need to be repeatedly sterilized by high temperature and high pressure steam, or those precision structures in minimally invasive surgical instruments that bear extreme stress and require extremely high strength and wear resistance, these characteristics of Udimet 520 can be brought into full play.

Through metal 3D printing technology, we can create an unprecedented complex internal structure for these medical devices, achieve the ultimate lightweight design, and greatly improve their functionality and service life.

C. Performance testing and characterization

For 3D printed Udimet 520 parts, performance testing and characterization are key to verifying their reliability. We ‘ve been working hard on this.

• Tensile test: This is the most basic. We will take samples in different directions and stretch them at room temperature and high temperature to determine the yield strength, tensile strength and elongation. We found that although the 3D printed Udimet 520 will show anisotropy in some directions, by optimizing the printing parameters and post-processing processes (such as hot isostatic pressing HIP), its comprehensive mechanical properties can reach or even exceed the level of traditional forgings.
• Fatigue testing: Fatigue life is critical for aero-engine components. We perform high-and low-cycle fatigue tests to simulate cyclic loading of components in real-world operation. The results show that the heat-treated 3D-printed Udimet 520 parts have fatigue properties comparable to conventionally manufactured parts, and even perform better under certain stress levels, which may be related to the unique fine grain structure of 3D printing.
• Creep test: under high temperature and long time working conditions, the material will creep. We will perform creep tests under high temperature and high stress to record the deformation and fracture time of the material. Udimet 520 itself is an alloy with excellent creep performance. After 3D printing, as long as the grain structure is controlled, its high temperature creep performance is still maintained at a very high level.
• Microstructural analysis: This is the key to “exploring the essence. Through SEM, TEM and other means, we will analyze the grain size, grain boundary characteristics, precipitation phase distribution and pore defects of 3D printing parts in detail. My personal experience is that the printing parameters have a great influence on the organization, such as laser power, scanning speed and layer thickness, which will directly affect the growth direction of grain and the formation of defects. Optimizing these parameters, combined with hot isostatic pressing, can significantly improve internal density and tissue uniformity, thereby improving overall performance.