What is a Metal 3D Printer and How Does it Work?

Metal 3D Printers

There has been a high increase in the demand for metal 3D printers for the past few years now. Due to this, there has been an increase in the production of metal 3D printers. Manufacturers are now introducing metal additive manufacturing machines. These machines are very easy to use, powerful, and very fast.

A good number of businesses are now integrating these 3D metal printers to make cost-effective metal prototypes and parts, which benefits from a wide variety of design linked to additive manufacturing. Metal 3D printers are crucial for use in a wide range of industries like medical, engineering, aerospace, and automotive among others.

The prices of metal 3D printer have been decreasing; however, these machines are still very expensive, with most printers ranging from $70K to about $1M.

In this guide, we have selected the best metal 3D printers. Our aim is to provide comprehensive details of different brands and what they have got to offer, at different price points, and with various metal 3D printing technologies.

How does Metal 3D Printing Work?

Metal 3D Printing

The production process is similar for DMLS and SLM. This is how this works:

There is inert gas in the build chamber (for instance argon) which helps to reduce the metal powder oxidation. After this, the metal powder is then heated to help build temperature.

The manufacturer spreads metal powder on the build platform. After this, there is a high-power laser which checks through the cross-section of the component. It then melts the particles of the metal together. This helps to create the next layer.  Also, the machine scans the whole area of the model to ensure the part has been solidly built.

After completing the scanning process, the build platform moves downwards, and then the recoater distributes another metal powder. The metal 3D printer continues to repeat this process until you have completed the whole part.

After completing build process, the parts would be encapsulated in the metal powder. Support structures help to attach these parts to the build platform.  Metal 3D printing technology builds support by integrating a similar material as the part. This is usually needed to help prevent the distortion and warping that may likely occur as a result of high processing temperatures.

The excess powder removes immediately the bin cools down to room temperature, and the machine heat treats the part while the parts are still fixed to the build platform. This helps to reduce residual stresses. The machine removes the component from the build plate by machining, cutting, or wiring EDM. After this, they are ready for use.

What are the Characteristics of Metal 3D Printing? Get to know SLM & DMLS

SLM & DMLS printer parameters

The machine manufacturer set all process parameters in DMLS and SLM.  In metal 3D printing, the layer height used varies between 20 to 50 microns. However, this depends on the metal powder’s properties like shape, flowability, and particle size distribution.

Typically, a metal 3D printing system has a build size of 250 x 150 x 150 mm. However, there are bigger machines having a build size of about 500 x 280 x 360 mm. Also, a metal 3D printer can achieve a dimensional accuracy of about ± 0.1 mm.

You can use metal printers for small batch manufacturing. However, metal 3D printing systems share similar capabilities with the batch manufacturing of SLA or FDM machines. The available print area restricts these machines, as you need to fix the parts to the build platform.

You can recycle the metal powder in DMLS and SLM.  The machine collects the unused powder after every print, sieves it and adds up fresh material for the next build.

In metal printing, supports structures are a form of waste. These structures are important in achieving a build but can drastically increase the amount of the required material.

Layer adhesion

Metal DMLS and SLM parts usually feature isotropic thermal and mechanical characteristics. These parts are very solid having low internal porosity which is below  0.2 – 0.5% in the as-printed state. Also, after thermal processing, it is usually close to none.

Metal printed parts are very strong and hard and they are usually more flexible than parts manufactured with a traditional method.  But, these metal printed parts are more vulnerable to fatigue.

For instance, the mechanical characteristics of the A360 die-cast alloy and AlSi10Mg EOS metal 3D printing alloy. The two materials are high in magnesium and silicon and also have a very similar chemical composition. Also, the printed parts feature higher hardness and greater mechanical properties compared to the wrought material.

The unprocessed material is in a granular form which has a built surface roughness. The built surface roughness is usually within 6-10 μm. This high surface roughness is responsible for the lower strength of fatigue.

Support structures & part orientation

Metal 3D Printer

Support structures are very important when it comes to metal 3D printing. This is because of to their high processing temperature due to the use of a lattice pattern.

In metal printing, support structures perform three functions which are:

  • They provide ideal platform to build on the next layer.
  • Also, they prevent any form of warping and fix the part properly to the build plate.
  • They as well function as heat sinks, which absorbs heat from the part and makes it cool down at in a controlled temperature.

Typically, parts are positioned at an angle. This helps to reduce the possibility of warping and as well enhance the strength of the part in very important directions. But, the amount of build time, required support, and the material waste will increase. Even the total cost will as well increase.

Randomized scan patterns can also reduce warping. Also, this type of scanning strategy protects against the creation of residual stresses in any direction and will as well include a surface texture to the part.

Due to the high cost of metal 3D printing, you can evaluate the characteristics of the part during processing using simulations. Also, topology optimization helps to increase mechanical performance and as well form lightweight parts. This optimization also reduces the possibility of warping and need for support structure.

Hollow sections & lightweight structures

Big hollow sections aren’t usually used as bed fusion processes in metal 3D printing. This is because it isn’t easy to remove support structures.

It is advisable to integrate tear-drop cross sections for internal channels that are bigger than Ø 8 mm. This is because internal channels don’t need any support structures. Also, there are more design rules on DMLS and SLM in this article.

You can design parts using cores and skin as an option to hollow sections. The use of scan speed and various laser power help to process skin and cores. Therefore, this offers different material properties.

Skin and cores are crucial when constructing parts that have big solid sections. This is because they minimize the possibility of warping and as well reduce print time. Also, they manufacture parts that have great surface quality and good stability.

In metal 3D printing, a strategy is commonly used for minimizing the weight of a part. This strategy involves the use of lattice structure. Also, topology optimization algorithms can help in designing lightweight, organic forms.

What are the Differences between SLM and DMLS

3D Printer Metal material

The two types of metal additive manufacturing processes are Direct Metal Laser Sintering (DMLS) and Selective Laser Melting (SLM). These technologies share some similarities. For instance, DMLS and SLM scan and melt the metal powder granules using a laser. The laser melts the powder granules and then creates a part layer-by-layer. Furthermore, both processes use metals that are in form of granules.

Despite sharing the same similarities, there are differences between DMLS and SLM. These differences  result from the basics of the particle bonding process. For instance, SLM utilizes metal powders that have a melting temperature that melts the particles at once. However, the powder used in DMLS comprises materials that have different melting points. This powder melts on a molecular level at very high temperatures. SLM manufactures parts just from a single metal. On the other hand, DMLS manufactures its parts mainly from metal alloys.

 DMLS and SLM are both integrated in industrial applications. These metal additive manufacturing processes manufacture end-use engineering products. In general, metal 3D printing refers to both processes in this article.

It is important to know that there are other additive manufacturing processes. These processes which are Ultrasonic Additive Manufacturing (UAM) and Electron Beam Melting (EBM) can also manufacture dense metal parts.  Although they have limited applications and they are not widely available. Therefore, we won’t really talk about them here.

Pros and Cons of Metal How Metal 3D Printer Work3D Additive Manufacturing

How Metal 3D Printer Work

Benefits of 3D printing metal parts

There are several advantages of 3D printing metal parts. These include:

  • Metal additive manufacturing provides a higher level of control and flexibility in the production line.
  • 3D printing technology has made it possible to create complex designs. Now, you can create highly detailed parts. These parts would need to be divided into several pieces using traditional methods.
  • Metal AM generates less waste than CNC milling. This is because metal AM only uses the material required for a particular part. This is the fact for extrusion-based methods since it is not always possible to re-use unbinded material.
  • 3D metal printing makes parts more or less hollow. It does this without reducing their resistance and strength unlike other methods where other parts are solid infill-wise.
  • The above-mentioned advantages f metal 3D printing can significantly minimize costs for each part. However, the high prices of metal 3D printer indicate an entry barrier. Based on your throughput, you can achieve a positive return on investment on time.

Limits of metal 3D printing

The prices of Metal AM systems are high. Also, their metal filaments and metal powders are very expensive. Furthermore, there are additional costs like learning curve and energy consumption.

Metal 3D printing poses safety threats and environmental constraints. Also, most metal 3D printers feature a huge footprint. Therefore, they require a particular operating environment with controlled humidity and temperatures.

Parts usually need post-processing in many cases, irrespective of the finishing touches for the surfaces.

The physical properties of metal 3D printing can be different from traditional methods. With metal 3D printing, you can find it hard to get similar physical properties as metal parts manufactured traditionally. Also, there are several factors you need to account for during the design process. You need to prepare before trying to 3D print a particular part.

Metal 3D Printing Materials

DMLS and SLM are more likely to manufacture parts from various metals and metal alloys. These metals include titanium, aluminum, cobalt chrome, Inconel, and stainless steel, titanium. Also, these materials conceal the demands of most industrial applications. Also, you can process precious metals, like silver, gold, palladium and platinum. However, they are majorly used for jewelry making and as such their applications are limited.

Metal powder used in metal 3D printing is costly. For instance, the price of 1Kg of stainless steel 316L powder ranges between $350 and$450. Therefore, it is crucial to reduce the part volume. Also, support is important for keeping the cost very low.

Metal 3D printing is compatible with other high-strength materials that are difficult to process. This is one of the major strength of of metal 3D printing. Metal 3D printing can help you to save significant cost and time by using it to produce a near-net-shape part which you can post-process later to a high surface finish.

Which metals can you 3D print?

You can 3D print a wide range of metal alloys and metal. The common metals you can 3D print include cobalt, nickel, bronze, aluminum, copper, titanium, steel, and cobalt-Chrome. Precious metals that can be 3D printed include platinum, gold, and silver.

Which metal 3D printing material formats are available?

You can find metal 3D printing material in different formats, providing to various methods of metal 3D printing. Filament, wire, and powder are the most common formats. Also, you can find metal 3D printing resin.

Post-processing Methods for Metal 3D printing

What is Metal 3D Printer

There are different post-processing techniques that enhance, the physical appearance, accuracy, and  the mechanical properties of the metal printed parts.

Removing the support structures and the loose powder are compulsory post-processing. Heat treatment   relieves the residual stresses and as well enhances the mechanical characteristics of the part.

You can integrate CNC machining for dimensionally crucial features like threads. Micro-machining, media blasting, polishing, and metal plating can enhance the quality of a surface and the strength of a metal printed part.

Metal 3D Printer Price: How much does a Metal 3D Printer Cost?

Generally, the prices of industrial metal 3D printer range from almost $30,000 to more than one million dollars for industrial-grade metal additive manufacturing systems.

Also, there are additional costs that need consideration. These include metal 3D printing materials, which price is about a few hundred USD/kg. Also, the costs associated with post-processing are another consideration.

Applications for Metal AM systems

There are a wide range of applications for metal 3D printing. Also, several industries integrate 3D printing. Some industries like automotive, aerospace, and medical are using metal AM. Whether it’s meant for replacement parts or tooling, there are several benefits of metal 3D printing and several industries enjoy these benefits.

But, every single metal part don’t actually benefit from metal additive manufacturing. Some metal 3D printing systems feature a relative capacity which helps serial production. However, the use of traditional methods is a much cheaper option for simple parts.

Metal AM is efficient when mass customizations and complex geometries are necessary.

Metal 3D Printing Services: order 3D metal parts online

Metal 3D printing is a perfect solution for professionals who have limited resources and low budgets.

You can easily order metal 3D parts on-demand. Also, you can do this without the need to get a 3D printer or purchase a particular material for one-time use.

Below are the most reliable 3D printing service providers that provide great metal printing services:

  • Hubs (ex 3D Hubs)
  • Stratasys
  • Sculpteo
  • Protolabs
  • Shapeways
  • i.materialise

Metal 3D Printing Technologies and Acronyms

A wide range of manufacturers create proprietary variations for technologies already existing. Then, they name them based on their registered names:

Directed Energy Deposition (DED)

This includes Electron Beam Melting , Direct Metal Tooling, Laser Engineered Net Shaping, Electron Beam Additive Manufacturing, and Laser Metal Deposition

Metal Material Jetting: This includes Metal Jet, Magnet-o-Jet, Single Pass Jetting , and Nanoparticle.

Lamination: This includes Ultrasonic Additive Manufacturing and Sheet Lamination.

Metal resin 3D printing: This includes stereolithography, Digital Light Processing, and FluidFM.

Metal 3D Printing FAQ

Does 3D printed metal have strength?

Metal 3D printed parts are much stronger than metal parts made with traditional manufacturing processes. The strength of this parts depend on some factors. One of these factors is the metal AM method integrated. Also, another factor is the conditions in which the parts are 3D printed.

In which year was 3D metal printing invented?

This 3D printing type was developed in the 1990s. The creation of Selective Laser Melting technology made it possible. 3D metal printing began to popularity from around 2010.

How does metal 3D printing work?

Metal 3D printing works in different ways. You can deposit several layers of metal filament one step at a time. This helps to produce a green part that will now undergo the debinding and sintering stages. These stages are very crucial in 3D metal printing. Also, you can use a laser to melt metal powder granules. Also, you can use an inkjet printhead to distribute drops of binding material on top of the powder.

What can metal 3D printing help you manufacture?

You can use Metal 3D printing for a lot of things. It is ideal for making complex, custom parts. Rather than using traditional methods to make these parts, metal 3D printing can be a great option as it makes it easy to make complex parts.

How expensive is metal 3D printing?

Metal 3D printing is expensive compared to other type of additive manufacturing processes. For instance, you can pay about $450 and above for just 1Kg of stainless steel 316L.

Is there a way to reduce metal 3D printing cost?

You can minimize metal 3D printing cost by simply reducing the material. There are two ways to achieve this. You can reduce the part volume and as well remove support structures where possible.

What are the common uses of metal 3D printing?

Most times, the common use of metal 3D printing  is for prototyping and producing good end-use parts. Also, 3D metal printing is ideal for manufacturing parts that have complex geometries. This manufacturing process can also minimize the number of metal components an assembly comprises.

Do you need support structures for metal 3D printing?

One of the most crucial things you need in metal 3D printing is support structures. They are always need when using metal 3D printing to produce parts. This is because of the very high processing temperature. In most cases, lattice pattern help to build support structures.

Can you use aluminum to 3D print parts?

Aluminum is a commonly used alloy metal in metal 3D printing. Also, this material is commonly used because of its strength, high flexibility, and great thermal properties. Aluminum can help in printing parts in industries like the automotive, aerospace and medical among others.

Can you use stainless steel to 3D print?

It is very possible to use stainless steel. Just like aluminum, steel can help you 3D print complex and larger parts. This is possible due to the strength of steel.

Conclusion

A good number of businesses are now integrating these 3D metal printers to make cost-effective metal prototypes and parts, which benefits from a wide variety of design linked to additive manufacturing.

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