4 Best Metals for 3D Printing

3D printing creates parts from a 3-dimensional drawing and prints products by placing layers of material in succession resulting in a finished product. 3D printing is an additive manufacturing technology that can manipulate metal materials to produce an almost unlimited selection of objects. Metal materials are available in powder and filament form for use with several 3D printing technologies. 3D printing allows the creation of complex metal geometries that are difficult or unattainable with conventional machining methods.

Metal 3D printing produces stronger parts that are lighter in weight than items produced by traditional subtractive processes such as machining. Studies have shown that 3D-printed metals can be much stronger than metals manufactured by conventional methods. Metal printing is a high-energy process that requires much higher melting temperatures than traditional plastic materials.

Direct Laser Sintering (DMLS) is a 3D printing process that uses a powder bed for the material printing shaping the metal dust into a completed part. The metal dust is shaped in the printer into a formed part. After printing, DMLS parts can be electro-polished to improve the surface finish. DMLS can also electro-polish parts to improve the overall surface finish.

Additional metal 3D printing powder bed technologies include; printing Selective Laser Sintering (SLS), Direct Metal Printing (DMP), and Laser Powder Bed Fusion (LPBF). The other metal 3D printing technologies include; Electron Beam Melting (EBM), Direct Energy Deposition (DED) – both powder and wire, Binder Jetting, and Bound Powder Deposition (BPD) – also referred to as Bound Powder Extrusion. 

The constraints to metal printing are whether the metal powder can be effectively bound to form objects and product availability.

Stainless Steel (SS) is a popular metal alloy composed of steel, chromium, and other elements known for its strength, durability, ductility, and corrosion resistance. It is used in a wide variety of applications and is popular in the aerospace, oil and gas, food service, and healthcare industries. While the material is somewhat expensive, it is less costly than titanium and nickel. Testing shows that 3D-printed stainless steel parts as 2 to 3 times as strong as steels manufactured by conventional manufacturing methods. 

For 3D printing of stainless steel alloys, below are the more commonly used materials, materials types, and technologies:

Common Materials:

• 316L
• 17-4GPH
• 15-5 PH

Material Types:

• Powder
• Filament

Common 3D Printing Technologies:

• Direct Laser Sintering (DMLS)
• Binder Jetting
• Direct Metal Deposition (DMD)

 

 

Material Types:

• Powder
• Filament

Common 3D Printing Technologies:

• Direct Laser Sintering (DMLS)
• Fused Filament Fabrication (FFF)

 

 

Material Types:

• Powder
• Filament

Common 3D Printing Technologies:

• Laser Powder Bed Fusion (LPBF)
• Direct Laser Sintering (DMLS)
• Direct Metal Printing (DMP)

Inconel 625 is a nickel-chromium-based superalloy designed to withstand high temperatures, stresses, and harsh environments (including chloride). Repeated heat cycles have little effect on Inconel 625. The strength, temperature, and corrosion resistance make the material ideal for aerospace applications. It is also used in automotive, chemical processing, and offshore applications such as the petroleum industry.

The Inconel 625 superalloy is expensive. This is why additive manufacturing techniques such as 3D printing are preferred to traditional subtractive manufacturing methods – there is little wasted material. Another is that the exceptional material characteristics make it extremely difficult to machine. Fortunately, it is reasonably easy to 3D print with DMLS. Direct Energy Deposit and Binder Jetting are also used to produce parts with Inconel 625.

A new additive manufacturing technology to produce Inconel parts is Atomic Diffusion. This technology is a powder 3D printing method similar to FDSM printing. After printing, the product is washed in a debinding solution and sintered in a furnace. The furnace burns away the plastic binder, and the metal powders form a more robust part. The process is highly accurate and a cost-effective alternative to producing the expensive material.

For 3D printing of Inconel 625, below are the more commonly used materials and technologies:

Common Materials:

• Ni625

Material Types:

• Powder
• Filament

Common 3D Printing Technologies:

• Direct Laser Sintering (DMLS)
• Direct Energy Deposition (DED)
• Binder Jetting
• Atomic Diffusion