Heat Treatment for Additive Manufacturing
Heat treatments can further improve final part properties such as hardness, elongation, and fatigue strength.
Why is Heat Treatment Important?
Often, when parts are 3D-printed, the process of differential heating and cooling introduces internal stresses as each layer becomes fused to create the part. The build undergoes contraction and expansion that can lead to cracking, warping, or in the worst-case scenario, failure due to pressures exerted on them when used in the final product. Heat treatment changes the microstructure of the part, yielding improved mechanical properties, such as strength, hardness, and fatigue resistance.
Heat treatment is an important post-processing step that can modify a material's microstructure to achieve desired mechanical properties and performance characteristics. The materials to the right represent the most common additive manufacturing alloys and their corresponding standard heat treatment conditions.
| Material | Standard Heat Treatment |
|---|---|
| AliSi10Mg (Aluminum) | Stress Relief |
| CoCr (Cobalt Chrome) | None |
| Inc718 (Nickel Superalloy) | Stress Relief |
| 316L (Stainless Steel) | Stress Relief |
| 17-4PH (Stainless Steel) | Solution Annealing & H900 Aging) |
| Ti6Al4V (Titanium Alloy) | Stress Relief |
Types of Heat Treatment for Additive Parts
There are four techniques that use heat to improve 3D-printed parts. The choice made regarding which one to use is based on geometry, material, and the intended application.
Stress Relief (Standard)
Prevents distortion or warping after printing and when removing parts from the build plate. Most DMLS materials receive stress relief as part of the standard manufacturing process. During printing, repeated heating and cooling cycles create internal stresses within the material. Applying heat while the part is still attached to the build plate allows the atoms to rearrange into a more stable state, relieving these stresses. This helps the part maintain its intended shape when removed from the build plate.
Hot Isostatic Pressing (HIP)
This process combines heat and pressure to help eliminate tiny internal air pockets, known as porosity. Although DMLS parts are already more than 99.5% dense, HIP is often used in fatigue-critical applications to further improve material performance and reliability. It is most commonly applied to Inconel, 17-4 PH stainless steel, and titanium alloys.
Custom
Custom heat treatment solutions are available, tailored to your requirements.
Solution Annealing & Aging
Solution annealing improves ductility and toughness while creating a more uniform microstructure. This heat treatment option is often used for parts that require enhanced mechanical properties. During solution annealing, the workpiece is heated to a high temperature, allowing alloying elements to distribute more evenly throughout the material while helping eliminate imperfections in the crystal lattice. The part is then rapidly cooled to lock in these microstructural changes.
Aging (precipitation hardening) increases the hardness and strength of a material through a controlled heat treatment process. Exposure to elevated temperatures allows the material to undergo atomic-level changes that create a stronger microstructure than the as-printed condition. The result is improved hardness, strength, and overall mechanical performance.
Note: Solution annealing and aging are often performed together to achieve a desired combination of properties, but these heat treatment processes can also be specified separately upon request.
Design Guidelines for Heat Treated 3D-Printed Parts
One way to avoid unwanted stress in your parts is to design rounded corners—fillets—which help smooth out the parts right from the start. While heat treatment reduces stresses, you should know that it does affect the grain structure of the material you've chosen to print. As mentioned above, be aware that not all materials are suitable for heat treatment. Our applications engineers can help guide you.
Common Applications for Heat Treated 3D-Printed Components
| Many industries rely on heat-treated 3D-printed metal parts to meet performance and durability requirements. By enhancing properties such as strength, hardness, and fatigue resistance, heat treatment helps optimize components for demanding applications across aerospace, medical, energy, automotive, and manufacturing sectors. |
| Aerospace & Defense | Medical Device & Implants | Energy & Power Generation | Automotive | Industrial Tooling & Manufacturing |
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