3D Printed Metal Parts: Higher Tech Means Higher Quality

(DGIwire) – Quality control (QC) is a must in all manufacturing—and the 3D printing of metal parts is no exception. Since the metal components used in everything from airplanes to medical prosthetics must adhere to the customer’s required dimensions down to extremely small scales, techniques must be utilized ensuring that every part delivered meets high standards.

Historically, however, this has been a challenge. As a recent article in Rapid Prototyping Journal noted, the quality of 3D-printed objects is a critical factor in the viability of widespread applications of low-cost 3D printing. One of the key strategies for securing this goal is known as in-process QC; according to the article, this is based on the premise that some signals can be detected automatically and quickly during the printing process to eliminate the potential for defects in the finished product.

“Software has been developed that can alert 3D metal manufacturers to variations in a part being created, and this allows the adjustment of the laser applying the material to be modified in ways that can offset those variations,” says John R. Rice, CEO of Sigma Labs. “In effect, we are making the part constant by making the machine variable.”

As Rice explains, the manufacturer’s goal is to have the “melt pool”—the material being formed into the final part—possess a pre-determined constant temperature no matter what the geometry or configuration of the part is. By calculating a metric known as Thermal Emissions Density™ (TED™) during manufacturing, the laser temperature can be modified at every stage. Doing so holds the potential of improving the percentage of usable 3D metal parts created from approximately 60 percent to around 90 percent on average, improving the rejection rate significantly.

Sigma, which has 18 patents applied-for with 17 still pending, has integrated these considerations into its INSPECT™ 2.0 software, a web-based application designed for seamlessly integrating data analytics with all metal 3D printing applications. For manufacturers that have already taken the first step in monitoring the printing process, Sigma Labs’ software provides access to powerful data analysis tools and baseline comparison technology. It enables plots of heating rate, cooling rate and peak temperature; real-time In-Process Quality Assurance™ (IPQA®) plots; part-by-part analysis of each layer; and more.

This latest development complements Sigma Labs’ development of a proprietary, patent-protected, physics-based quality assurance software suite called PrintRite3D® that transforms the 3D printing process. In contrast to traditional quality assurance that is performed after-the-fact, PrintRite3D® works in real-time during the printing process to assist manufacturing engineers in sorting acceptable from suspect components.

“Bringing down the substantial error rate that has been inherent to date in 3D metal manufacturing is a must for progressing this technology to its full potential and software now available can go far in advancing this goal,” Rice adds.