Common material in metal 3D printing: 316L Stainless Steel

As a representative austenitic stainless steel, 316L stainless steel is well-known for its excellent corrosion resistance, strength and durability, and has become a key material in the field of 3D printing. 316L stainless steel can be used to print various parts with complex structures and is widely used in aerospace, medical equipment, petrochemical and other industries. Especially in the biomedical field, 316L is used to print human implants such as hip joints and dental restorations due to its excellent biocompatibility and corrosion resistance. This article discusses the material advantages of 316L stainless steel, the methods used for its 3D printing and its industry applications.

Source:https://am-material.com/industry-news/preparation-and-application-of-316l-stainless-steel-powder/

Advantages of 316L stainless steel as a 3D printing material

1. Corrosion resistance: 316L stainless steel has high corrosion resistance, especially for seawater, organic acids, alkalis, salts and many inorganic compounds, which enables the printed products to maintain a good service life in a variety of harsh environments.

2. High strength and heat resistance: After 3D printing, 316L stainless steel can still maintain high strength and hardness as a whole, and has good high temperature strength and lasting strength, which is suitable for use in high temperature environments.

3. Biocompatibility: 316L stainless steel will not cause obvious rejection reactions when implanted in the human body for a long time, and it is not easy to cause allergies, so it is widely used in the field of medical implants.

4. Excellent printing performance: 316L stainless steel powder is easy to melt, and the microstructure after cooling and solidification is uniform and dense, which is conducive to ensuring the mechanical properties and dimensional accuracy of 3D printed parts.

5. Green and environmentally friendly: Stainless steel 316L produces less waste during production and use, which is in line with the concept of modern industry pursuing sustainable development.

3D printing industry application of 316L stainless steel

1. Aerospace

316L stainless steel can be used to manufacture lightweight complex parts in the aerospace field, such as hollow brackets, grid frames and combustion chamber pipes. These parts not only require excellent corrosion resistance and high strength, but also need to be able to withstand extreme temperatures and high pressure environments.

2. Automobile manufacturing

In the field of automobile manufacturing, 316L stainless steel is used to print complex parts such as turbocharger housings, exhaust system components and brake parts due to its high strength and corrosion resistance.

3. Medical devices

In the medical industry, 316L stainless steel is widely used to manufacture implants and surgical tools. Its excellent biocompatibility and corrosion resistance make it an ideal choice for customized implants such as bone plates, bone nails and hip joints.

4. Industrial field

In the industrial field, 316L stainless steel is used to print high-precision molds and chemical equipment. For example, injection molds and die-casting molds can be designed with complex cooling channels through 3D printing technology, thereby improving production efficiency and extending mold life. In addition, its excellent corrosion resistance makes it very suitable for manufacturing durable pipes, valves and reactor components in harsh chemical environments.

3D printing metal production process

1. Selective laser melting (SLM)

Selective laser melting (SLM) is the most common metal 3D printing technology, accounting for about 80% of the metal 3D printer market, and is also a common printing method for 316L stainless steel. This technology uses laser as the energy source, and scans the metal powder bed layer by layer according to the path planned in the slice model. The scanned metal powder is melted and solidified to finally obtain the metal parts designed by the model. SLM 3D printing technology can directly form metal parts that are nearly fully dense and have good mechanical properties. Among them, steel and steel alloys are the most popular materials for SLM 3D printing machines and are widely used in business.

2. Binder Jetting

Binder jetting is another 3D printing technology based on powder bed. The difference is that it does not melt by laser, but uses an inkjet print head to spray the binder onto the powder so that the powder is bonded together in the selected area, and stacked layer by layer to produce the desired object. Binder jetting is also considered to be the most promising method for large-scale production in metal 3D printing technology. In addition, the material properties of metal binder jet parts are similar to those of parts produced by traditional metal injection molding.

3. Fused Deposition Modeling (FDM)

FDM printers are common in plastic filaments. In metal printing, FDM 3D printing is combined with stainless steel powder-injected filaments, which are usually composed of about 80% metal and 20% plastic mixture. After printing is completed, post-processing is required to remove the plastic to obtain a metal part similar to metal injection molding, but this may result in a volume loss of up to one-third of the part. Wire is not the only material option for FDM printing. Combining stainless steel particles and metal polymer composites, the prototype model is first printed, and then the final dense stainless steel metal part is manufactured through degreasing and sintering processes.

4. Combined metal deposition

The combined metal deposition technology is similar to FDM. It uses metal wire material to melt the wire by induction and other methods, and then controls the surface tension of the droplets on the nozzle under the action of electrostatic force or magnetic field, and deposits the metal droplets on the forming platform. This technology is closer to traditional metal injection molding (MIM) technology. In addition, post-processing is required to remove the binder and heat treatment in the furnace for final sintering. This technology is mainly used to manufacture steel prototype parts. Typical applications include molding tools, stamping dies, nozzles, impellers, fixtures, and heat exchangers.

5. Powder bed electron beam melting (EBM)

Electron beam melting (EBM) is another powder bed melting technology. Its working principle is similar to selective laser melting (SLM), except that it uses a higher temperature electron beam instead of a laser as an energy source. The recoater applies a layer of powder to the build platform, and then the electron beam selectively melts each cross-section of the powder. After each layer is completed, the print platform plate will drop, and the layers will be stacked to form an object. EBM is much faster than SLM, but the surface smoothness and precision of the manufactured parts are not as good as SLM. In addition, the EBM process is carried out in a vacuum chamber, which reduces material impurities that may cause defects.

With the increasing maturity of 3D printing technology, the application scenarios of 316L stainless steel will be further expanded to provide more efficient, precise and innovative solutions for various industries. If you are looking for professional 316L stainless steel 3D printing services, JLC3DP can support you and help you achieve a one-stop solution from design to high-performance part manufacturing.