Today, what 3D printer can print is more than plastic parts but also metal parts. Metal 3D printing is currently on the rise. Why do companies like to use 3D printing for their metal parts? Are you looking for a metal 3D printing service too? And how can you get the most out of this kind of metal prototype manufacturing technique? There are three commonly used techniques: DMLS/SLM, binder jetting, and metal extrusion, which one should you choose? Well, this article is to give you an overview of today’s popular metal 3D printing to explore its processes, benefits, and challenges, and to introduce some popular applications.

How do metal 3D printer work?

The working principle of a metal 3D printer is the much same as other 3D printers. It also builds parts by adding materials layer by layer based on a CAD/3D design.

DMLS/SLM

SLM (Selective Laser Melting) is a rapid metal prototype manufacturing technique that uses a high power-density laser to melt and fuse metallic materials together, layer by layer. DMLS (Direct Metal Laser Sintering) is similar to SLM. The difference is temperature. The DMLS process doesn’t require melting the materials fully. 

Binder Jetting

In the binder jetting process, there are two materials used: powder-based materials and blinders. A liquid bonding agent is deposited to join powder-based materials. The binder acts as an adhesive between powder layers. The materials are then bonded layer by layer to form an object. But to get a fully-metal part, the object needs to be thermally post-processed (sintered) to remove the binder.

Metal Material Extrusion

It is a fairly new additive metal prototype manufacturing technique. Its process is much similar to the widely used FDM technique. A filament, consisting of thermoplastic material and metallic particles, is heated and extruded through a nozzle and then deposited layer by layer. To create a fully-metal part, post-processing (deboning and sintering) is required.

Benefits of Metal 3D Printing

Metal 3D printing is a powerful prototyping tool. It comes with many unique benefits that make it the best option when it comes to the prototyping and manufacturing of metal parts.

Here is the summary of the most important advantages:

1. More geometrically complex design

Compared to traditional metal prototype manufacturing processes, for example, CNC machining, the greatest strength of metal 3D printing lies in its extraordinary flexibility in design. It can deal with more complex geometries. 

More importantly, the increased geometric complexity of a part has few effects on the manufacturing cost. This means you can get a metal part with more complex geometries like organic, topology structures without extra costs, which is impossible to achieve through other processes.

2. Increased part functionality

With the metal 3D printing technique, it is possible to manufacture parts with internal structure, which will increase the overall performance of parts.

For example, when you need to make a mold for injection molding, you can manufacture one with internal channels for conformal cooling through DMLS/SLM. It can significantly reduce injection cycles. 

In addition, you can use the Metal Extrusion technique to produce jigs and fixtures with complex geometric structures.

3. Excellent materials properties

Parts manufactured through DMLS/SLM or Binder Jetting processes have material strength that is comparable to the wrought metal, sometimes, even better. This makes metal 3D printed parts to be widely applied in the most demanding industries, like aerospace.

Limitations of Metal 3D Printing

However, despite so many benefits of metal 3D printing, currently, it also comes with some limitations that do not make it always the best option for metal prototype manufacturing.

1. Higher cost

The cost of a metal 3D printed part is higher than traditional manufacturing methods. The use of this fast prototyping service makes economic sense only when your part requires considerable improvement in performance.

2. Limited economies of scale

Another limitation is that metal 3D printing is suited only to produce a small number of parts, both in economic and technical senses. And the unit price is almost unchanged, no matter how many parts to manufacture.

Yet, the industry is working hard towards metal 3D printing systems that can streamline production. Someday, it might be technically and economically applicable to mass production.

3. Post-processing is always required

Almost no matter which metal 3D printing technique, to get a fully-metal part, some post-processing treatments, such as thermal treatment, machining, polishing, and so on, are needed. It will add costs to production and times to delivery.

Applications of Metal 3D Printing

Here are some key industrial applications of metal 3D printing technology to help you make the decision according to the industry you are in.

Aerospace

It is of paramount importance to create aerospace parts with a lightweight structure for the space industry. As the larger weight of an aircraft, the much higher expense to launch it. And usually, critical aerospace parts are geometrically complex and are required to have higher performance. Therefore, metal 3D printing of topology optimized aerospace components has great potential.

Automotive 

In the automotive industry, metal 3D printing technology is being increasingly adopted to produce high-performance and lighter parts; for example, the parts for racing cars that require high impact resistance performance and excellent strength-to-weight ratio.

Medical

Metal 3D printing has an impressive ability to create organic structures, which makes it a very appealing solution for the medical industry. Today, medical implants made from bio-compatible materials, such as titanium, are one of the major applications of metal 3D printing in the medical field.

R&D

The Metal Extrusion technique is mainly applied to metal prototype manufacturing in the new product development cycle for design testing and verifying. When compared to other prototyping solutions, it is more time-saving. It can significantly reduce the time-to-market of a new product, giving companies a competitive edge and win their markets.

In this post, we touched upon some you need to know about metal 3D printing basically. If this technology is new to you and you want to try this service, this article may give you the basic knowledge and help you make the right choice.