Additive Manufacturing Heat Treating Services

Solution Annealing, Stress Relieving, Aging, Sintering and More

Heat Treating Services for Additive Manufacturing

Additive Manufacturing Vacuum Heat Treating — RPM Innovations, Inc. complex titanium hollow ribbon additive manufactured part heat treated at Solar Atmospheres (post heat treating)

Why is Heat Treating Important to Metal Additive Manufactured Components?

During 3D printing, differential heating and cooling often introduce internal stresses as each layer fuses to form the part. This process causes contraction and expansion, potentially leading to issues such as cracking, warping, or, in extreme cases, structural failure when the part is subjected to pressure in its final application. Heat treatment can alleviate these stresses by altering the microstructure of the material, resulting in enhanced mechanical properties, including increased strength, hardness, and fatigue resistance.

Types of Heat Treatment for Additive Parts

Heat treatment is a crucial step in enhancing the performance and durability of 3D-printed parts. There are four primary methods used, and the choice depends on factors such as geometry, material, and the intended application.

Stress Relieving: Stress relieving minimizes internal stresses by allowing the atoms in the material to rearrange into a more stable configuration. By applying heat, the process smooths out any undesirable interactions between layers. This method is effective for most materials, except for cobalt chrome (CoCr).

Hot Isostatic Pressing (HIP): HIP combines heat and pressure to eliminate internal microporosity, further reducing residual stress. Even parts created via Direct Metal Laser Sintering (DMLS), which achieve nearly 100% density, can benefit from HIP. This process is especially beneficial for materials like Inconel and stainless steel 17-4 PH. Solar Atmospheres collaborates with partners such as Kittyhawk, Inc. and Pressure Technology, Inc. to provide HIP services.

Solution Annealing: Solution annealing enhances the mechanical properties of production-grade parts. The material is heated to a high temperature and rapidly cooled, transforming its microstructure to improve ductility. This method is most commonly used for aluminum parts.

Aging (H900 Aging): Aging strengthens parts by exposing them to elevated temperatures. The heat reinforces imperfections within the metal’s lattice structure, increasing hardness and tensile strength. This method is particularly effective for applications requiring enhanced durability.

Since the ultimate goal of Additive Manufacturing is to produce near-net components, thereby eliminating machining waste, vacuum heat treating is well situated to be a lasting partner with printing technologies for many years. Only the vacuum heat treating process can produce the critical temperature uniformity (±2°F) and the vital heating and cooling rates by thermocoupling parts in direct contact with the metal. Additionally, the vacuum heat treating process has the ability to attain vacuum levels of 1 X 10^-6 Torr which is necessary to produce the clean oxide-free results. These critical thermal and atmospheric conditions only aid in producing strong, ductile, and crack free metallurgical results that are paramount with the new metallurgy of 3D metal printing.

Clean MIM, PIM and Binder Jet processing as well!