Introduction to Metal 3D Printing: How Does it Work?

With the ever-growing popularity of 3D printing technology, it is no surprise that there is also a metal 3D printing process. Metal 3D printing offers several advantages over traditional manufacturing methods, including reduced material wastage, shorter lead times, and the ability to create highly complex parts. But how does it work?

We will start by defining what 3D printing is so you can have a better understanding of the technology, and then delve into the world of 3D metal printing.

What is the Meaning of 3D Printing?

3D printing is used to mean a process where computer-generated designs are turned into physical objects by adding layers of material one after the other. 3D printing technology has recently become widely used due to the introduction of affordable 3D printers.

3D printing works by following a digital file. This file contains all the necessary information that the 3D printer needs to know in order to produce the desired object.

The file is fed into a computer which then controls the 3D printer nozzle or head to build up the object layer by layer from the bottom up. The material used can be anything from plastic and metal to food.

Metal 3D Printing

To start us off, what is 3d metal printing technology? Metal 3D printing, put simply, is an additive Fertigung process that creates metal parts using metal powder (or paste) and instructions from a digital file.

The process works by building up the desired object from the bottom upward, in layers, using finely powdered metal and a binding agent or powdered metal and laser.

The history of 3D metal printing goes back to the 1980s when a process called selective laser melting (SLM) was developed.

Today, there exist a number of metal 3D printing processes, with each offering its advantages. Before we take a look at the different types of metal 3D printing, let’s first see how it works.

How Metal 3D Printing Works

The process of using metal for 3D printing, just like any other type of 3D printing, involves a few steps. There are highlighted below, from the start to the last stage.

• First, a digital file of the object to be printed is created using computer-aided design (CAD) software. This file is then processed by slicing software which breaks down the object into thin layers.
• Once the file is sliced, it is ready to be sent to the 3D printer. The 3D printer will then build up the object in layers using finely powdered metal and a binding agent or laser.
• The binding agent joins the powder particles before the object is heated to cause the particles to fuse.
• The laser is used to weld the metal powder particles together so that they form a solid object. The binding agent is then removed, leaving behind the finished 3D-printed metal object.
• The final part is the posts-processing stage. In metal 3D printing, post processing involves surface finishing methods to improve the strength, durability, and aesthetics of the 3D-printed metal object.

Types of Metal 3D Printing

As we mentioned above, there exist a number of different techniques when it comes to 3D printing of metal. The most common types are metal powder bed fusion (PBF), direct metal deposition (DMD), binder jetting, and metal extrusion. Let’s take a look at each of these in types of 3D metal printing technologies in turn.

1. Metal Powder Bed Fusion

Metal powder bed fusion metal printing is the most widely used type of metal 3D printing process. It works by depositing thin layers of metal powder onto a build platform and then fusing them using a laser or an electron beam to fuse the powder particles.

This 3D metal printing technology is best suited for small to medium-sized parts with complex geometries. It produces parts with great mechanical properties and accuracy and is perfectly suited for applications that require those, such as in the aerospace and medical industries.

Variations of the PBF process include selective laser melting (SLM), direct metal laser sintering (DMLS), and electron beam melting (EBM) printing methods.

2. Direct Metal Deposition

Direct metal deposition (DMD) is a means of 3D printing with metal that works by depositing material onto a built platform layer by layer using an extrusion process. A laser, arc, or plasma torch is then used to heat and melt the metal. An electron beam may also be used.

Direct metal deposition offers the advantage of being very affordable, fast, and good for large-volume parts. However, parts manufactured using this method usually require machining to improve surface quality.

3. Binder Jetting

Binder jetting works by depositing thin layers of metal powder onto a build platform and then using a jetting system to apply a binding agent to the powder. The binding agent holds the powder particles together and creates a solid object.

The object, once formed, is finally heated to remove the binder and fuse the metal powder and then is finished as necessary. This metal 3D printing method is best suited for large-scale objects and objects with complex geometries. It is also affordable and fast.

4. Metal Extrusion

Many small-scale businesses are using this type of metal 3D printing and for these reasons: it’s an affordable metal 3D printing method, easy to set up and generally usable. Metal extrusion 3D printers are also readily available.

Extrusion-based 3D metal printing works by using polymer filaments that have been impregnated with metal powder. The filaments are melted and extruded through a nozzle onto the build platform where they are joined to create the final object.

After the process is complete, the object is washed to remove the polymer and is then sintered in a furnace to fuse the metal powder and create a solid object.

Metal extrusion is not one of the best metal 3D printing techniques for complex parts. It mostly fits small objects with simple geometries. The main advantage of this method is that it is very affordable. However, the quality of objects produced is normally not as high as that of other methods.

Metal 3D Printing Applications

Parts and objects produced using metal 3D printing are used in a variety of industries. Mostly, they find applications in aerospace, automotive, medical, and many other sectors, both for functional parts and prototyping.

• In the aerospace industry, metal 3D-printed parts offer the benefits of being lightweight and the ability to create complex part geometries.
• In the automotive industry, metal 3D-printed parts are used to create prototypes and low-volume production runs of customized parts.
• For example, a company might use metal 3D printing to produce a small batch of custom engine parts for a new car model.
• In the medical industry, metal 3D-printed parts and devices are being used with great success. Metal 3D printing offers the ability to create customized products that perfectly match needs.

With metal 3D printing, rapid prototyping is easier and quicker in many different industries; and less expensive. That’s in addition to parts that you can actually use.

How Much Does Metal 3D Printing Cost?

The metal 3D printing cost depends on a number of factors. These include the type of printer used, the type of metal, the size and complexity of the object being printed, and the amount of post-processing required.

That said, metal printing is generally costly. This is because of its use of metal material, especially in powder form, and the need for post-processing steps such as sintering.

In addition to the cost of 3D metal printing materials, the printer itself can be very expensive. For example, an industrial-grade binder jetting machine can cost upwards of $150 000.

That being said, there are now many service providers that offer metal 3D printing services. This is a great option for businesses that do not want to invest in their own equipment.

Schlussfolgerung

Metal 3D printing is a great option for businesses that need to produce metal parts quickly and affordably, more preferably prototypes. Before deciding if metal 3D printing is the right option for your business, it’s important to consider the type of objects you need to produce, the quality requirements, and the cost.