Detailed Description: Spherical Stainless Steel Alloy Powder for AM
& Thermal Spray
This is a high-quality metal powder that serves as a versatile
feedstock for multiple advanced manufacturing techniques.
1. Powder Characteristics
Morphology: Spherical.
This is the most critical feature.
Production Method: Almost exclusively Gas Atomization.
Molten stainless steel is dispersed by a high-pressure inert gas
(Argon, Nitrogen) to form fine, spherical droplets that solidify
into powder.
Key Properties:
- Excellent Flowability: Spherical particles roll over each other
easily, which is essential for both automated powder spreading in
3D printers and consistent feeding in thermal spray guns.
- High Packing Density: Spheres pack together more efficiently than
irregular shapes, leading to denser coatings in thermal spray and
higher part density in 3D printing.
- Low Oxygen Content: The inert gas during atomization minimizes
oxidation, which is vital for achieving good mechanical properties
and corrosion resistance in the final part or coating.
Particle Size Distribution (PSD):
- For 3D Printing (L-PBF): Fine powder, typically 15-45 µm.
- For Thermal Spray & 3D Printing (DED): Coarser powder, typically
45-106 µm or 53-150 µm. This size is ideal for being carried by the
gas stream in thermal spray and DED systems.
2. How It Is Used in Each Process
A. In 3D Printing (Additive Manufacturing)
- Laser Powder Bed Fusion (L-PBF): A thin layer of this fine
spherical powder is spread across a build platform. A laser then
selectively melts the powder according to the part's cross-section,
building a solid, dense object layer by layer.
- Directed Energy Deposition (DED): The coarser spherical powder is
blown through a nozzle into a focused laser beam, creating a melt
pool on a substrate. This builds up material, either to create a
new part or to add material to an existing component (e.g., for
repair or feature addition).
B. In Thermal Spraying
- Process: The spherical powder is fed into a high-temperature,
high-velocity stream (in Plasma Spray or HVOF). The particles are
heated to a molten or semi-molten state and accelerated onto a
prepared substrate surface.
- Result: Upon impact, the particles flatten, splatter, and rapidly
solidify, forming a tightly bonded coating. The spherical
morphology ensures consistent feeding and melting, leading to a
uniform, low-porosity coating.
3. Common Stainless Steel Grades Used
The same spherical powder grades are used in both fields:
- 316L: The most common, due to its excellent corrosion resistance.
- 304/L: For general purpose corrosion protection.
- 17-4PH: For applications requiring high strength and hardness after
heat treatment.
- 420: For wear-resistant surfaces and tools.
4. Advantages of Using Spherical Powder for These Applications
| Application | Advantages of Spherical Powder |
|---|
| 3D Printing (L-PBF) | Enables smooth, consistent recoating of layers; high part density
(>99%); excellent mechanical properties; good surface finish. |
| 3D Printing (DED) | Consistent flow from the feeder nozzle; stable melt pool; high
deposition efficiency. |
| Thermal Spraying | High deposition efficiency; uniform, dense coatings with low oxide
content; consistent feed rate without clogging. |
Summary: The Correct Interpretation
The description "3D printed thermal sprayed spherical stainless
steel alloy powder" is best understood as:
A single type of high-quality, gas-atomized, spherical stainless
steel powder that is produced to a specification making it suitable
as a feedstock for two different advanced manufacturing processes:
- 3D Printing (specifically L-PBF or DED) to create solid, complex
parts.
- Thermal Spraying (specifically Plasma Spray or HVOF) to apply
protective, wear-resistant, or corrosion-resistant coatings onto
existing components.
