3D Metal Printing: What Metals Are Best?

(DGIwire) – Metal additive manufacturing (AM)—better known to the general public as 3D metal printing—is steadily increasing in popularity. One of the chief questions facing companies that are considering the use of this manufacturing option involves the ideal choice of metals. In a recent article in Machine Design, Sigma Labs co-founder Mark Cola discussed this and several other considerations—such as the important of in-process quality assurance to ensure integrity of the printed metal parts.

As Cola reports, the most commonly used metal and alloy powders for laser- and electron beam-assisted AM powder-bed fusion processes are aluminum-, titanium- and nickel-based alloys as well as stainless steels, principally because they have been historically prescribed for use in commercial and consumer products. Other lesser-known metals include copper alloys, bronze, precious metals (such as gold and platinum), cobalt-chrome alloys and refractory metals.

“While the range of metals suitable for AM is wide, the manufacturing of high-quality powder remains a critical challenge due to its high surface area, susceptibility to oxidation and the ability to detect the effects of such anomalies on part quality,” Cola notes. “Separately, the AM process conditions—particularly the thermal history—drive the resulting structure and properties of metal parts. It is for this reason that in-process quality assurance is so critical.”

Sigma Labs’ PrintRite3D® suite of products presents a significant value proposition to OEMs and manufacturers, as it is designed to increase production yield of 3D metal manufactured parts and to shorten time to market. PrintRite3D® combines inspection, feedback, data collection and critical analysis into a unified platform.

The first component of the PrintRite3D® platform is SENSORPAK®, which uses multisensors and affiliated hardware to collect real-time data on additive manufacturing processes. Comprising a set of on-axis in-process sensors, it enables part quality assessment during manufacturing, and is capable of measuring the true in-process state variables associated with an additive manufacturing process.

This component is complemented by INSPECT®, which comprises software for in-process inspection of metallurgical properties. It uses sensor data and establishes in-process metrics for each metal or alloy during the process. It provides manufacturing engineers with part quality reports based on rigorous statistical analysis of manufacturing process data, and allows for interrogation of suspect part data that can be used for process improvement and optimization.

Sigma Labs is further refining the PrintRite3D® suite to include two additional components: CONTOUR®, a layer-by-layer geometry measurement tool, and ANALYTICS®, consisting of software and a database that will link all critical data over multiple builds, machines and fabrication sites over time.

“The challenges surrounding metal AM may appear imposing, but the advent of in-process quality assurance platforms that can easily be integrated into manufacturing pipelines makes the endeavor ultimately rewarding and cost-effective for businesses in many sectors,” Cola adds.