Emily Newton Emily Newton
Editor in Chief

How Manufacturers Can Improve the Quality of Their Metal 3D Printed Parts

September 29, 2021


Metal 3D-printing technology is becoming widely adopted as manufacturing professionals realize it can lead to cost savings and increased efficiency. However, optimizing results requires staying focused on quality, and here we discuss how manufacturers can help ensure quality in their metal additive manufacturing (AM) processes.

Select the Right Powder

Choosing the most appropriate powder before starting a metal AM project can significantly impact overall success. Not all powders work well for AM, therefore manufacturers should carefully evaluate powder properties such as tensile strength, elongation and hardness.

Mikael Schuisky, AM business unit manager at Sandvik Additive Manufacturing, explains some specifics in depth, pointing out how the powder-manufacturing process matters. “First, not all metal powders are the same,” he tells Manufacturing Engineering magazine, “as there are a number of different industrial processes used to manufacture them. The most common of these is gas atomization, although plasma atomization and the plasma rotate electrode process also are used.” 

Schuisky describes some of the ideal characteristics required of metal powders for AM. For example, they should have a spherical shape to promote good flowability. Additionally, manufacturers should check that the chosen powder shows low levels of satelliting--when smaller particles get stuck to the powder’s surface, interfering with flow and packing density. 

He also recommends use of powders with low retained moisture content, and cautions that significant variability exists among suppliers, even when they use the same processes to manufacture the powders.

Listen to Client Needs

The common quality indicators of metal 3D printed parts include consistency and durability. However, achieving high metrics in these areas may prove insufficient if manufacturers fail to consider a customer’s specific needs and ensure the printed metal parts meet or exceed those requirements.

For example, researchers at the University of Bath recently received permission to conduct human trials for 3D printed titanium-alloy knee implants. Developers hope that these devices will bring more stability and comfort to osteoarthritis sufferers than implants manufactured from more traditional means.  They also believe that knee replacements should prove helpful for everyone, not just those in late stages of the disease. In this case, and in others, keep in mind that suppliers may define quality differently from their customers, although there’s almost certainly some crossover. Spend time with your current and potential customers to determine their expectations and whether you can meet them using metal AM. 

Consider a Smart-Monitoring Solution

Many of today’s manufacturing decision-makers realize it makes good business sense to implement Internet of Things (IoT) technology in their factories. Results can include reduced downtime costs, particularly when sensors predict equipment outages before they occur. Such connected solutions also can improve the quality of metal AM parts. 

A 2017 academic paper published in the Journal of Powder Metallurgy and Mining explains the potential benefits of combining IoT with AM, allowing an operator to remotely monitor and control an AM machine via a web-based interface. The complementing software allows for the monitoring of print parameters such as the temperature of the build plate and printer-head speed, and the number of layers printed. 

Implement Computer Tomography

Computed tomography (CT) scans offer a reliable way to verify that metal AM quality meets minimum standards. Besides checking for structural integrity and revealing any evidence of unwanted porosity, this nondestructive test method can measure a build’s dimensional accuracy. 

CT scanning relies on an X-ray to produce digital slices of a test object, displaying it from numerous angles. Software then turns the two-dimensional images into a 3D model with an accompanying dataset. Manufacturers can study the model to find cracks, voids and other defects in the build, and to evaluate internal part features that otherwise would require cross-sectioning.

CT scanning also can stimulate trust from decision-makers in industries where metal AM technology remains relatively new. For example, manufacturers in the aerospace industry want assurance and evidence that metal AM parts will perform as well as or better than their billet-machined counterparts.

Finally, CT scanning enables manufacturers to verify how hybrid powder blends and newer alloys stack up against more traditional options. The technology even allows analyzing high-resolution images of individual powder grains. Spotting problems such as porosity and irregular grain sizes at that early stage minimizes the chances of poor-quality outcomes that could erode client trust.

Start Affecting Metal AM Quality Today

Counting high-quality results among your ongoing goals while making Metal AM parts can bolster your facility’s reputation and reduce the expenses associated with preventable defects. These suggestions will get you off to a great start in achieving measurable progress and determining where weaknesses lie. 3DMP

Industry-Related Terms: Additive manufacturing, Build plate, Porosity
View Glossary of 3D Metal Printing Terms

Technologies: Post Processing

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