Article

The Scoop on the Scope of DMLS Metals

DMLS is an additive manufacturing process which 3D prints metal parts. Laser energy melts powder metals in an enclosed build chamber, layer by layer, to result in fully realized parts; imagine fine metallic sand is being zapped by space lasers, shooting out sparks of stardust as it melts designs (at least, that’s what it looks like to us). Metals Stratasys Direct Manufacturing 3D prints with include Stainless Steel 17-4PH, Stainless Steel 316L, Aluminum AlSi10Mg, Inconel 625, Inconel 718, Titanium Ti64, and Cobalt Chrome CoCrMo.

Inconel 625, Inconel 718, Titanium Ti64, and Cobalt Chrome CoCrMo are best suited for high-end, production applications. These metals will typically perform with higher tensile strengths. Aluminium AlSi10Mg can build faster than other DMLS materials. While it has good thermal properties, strength and hardness, its speed has made it a favorite among lower cost prototypes. Titanium Ti64 meets ASTM F1472 requirements. It is most commonly applied to complex aerospace designs, like engines and turbines. Cobalt Chrome CoCrMo, which has a history of meeting ISO specs for biocompatibility, has excellent corrosion resistance and is more favored for medical and dental prototypes. Inconel 625 and Inconel 718 meet identical hardness and temperature performances, with 718 yielding slightly higher for strength.

A Tale of Two Steels

 

Stainless Steel 17-4PH & 316L Comparison Chart
Stainless Steel 17-4PH	Stainless Steel 316L
Magnetic	Non-magnetic
Strengthening through Heat Treatment	Cannot undergo Heat Treatment
Good Hardness	Good Ductility
Good Corrosion Resistance	Higher Corrosion Resistance
Good Weldability	Excellent Weldability
Slower Build Time (can impact cost)	Faster Build Time (can be more cost effective)

Stainless Steel 17-4PH

Strengths:

• Performs well in high strength applications requiring above average hardness mechanical properties
• Can be heat treated to improve strength and hardness, and exceed the hardness properties of Stainless Steel 316L
• Magnetic

Weaknesses

• Builds slightly slower than 316L

Applications

• Magnetic applications
• Small parts
• Protoypes
• End-use spare parts

Stainless Steel 316L

Strengths:

• Higher ductility than Stainless Steel 17-4PH
• Non-magnetic
• Higher corrosion resistance
• Excellent for general purpose prototyping
• More ideal for welding applications
• Faster build time

Weaknesses

• Cannot undergo heat treatment

Applications

• Consumer goods
• Food processing
• Chemical processing
• Marine and medical devices

Mechanical Properties of Stainless Steel 17-4PH & 316L

 

Design Tips for DMLS

DMLS parts built with Stainless Steel 17-4PH and 316L achieve layer thickness, or resolution, as small as 40-60 microns on the Z axis, with minimum feature sizes around 0.012” – 0.016”. Minimum recommended wall thickness for these materials is 0.012” – 0.016” and minimum hole diameter is 0.035” – 0.045”. When designing for DMLS, keep in mind that angles below 45° will require build supports; Stratasys Direct Manufacturing build engineers will apply supports for designs and arrange designs on the build platform to assure the best build is achieved. Standard tolerances for DMLS are ± 0.005” for the first inch and ± 0.002”/” thereafter.

DMLS prototypes and end-use components and parts offer a more affordable method to reach complex designs for metal applications. Visit our materials page to learn more about the DMLS metals and their mechanical properties.