by Ryan Kircher,
Throughout the evolution of technology, hardware advances reach a tipping point for widespread adoption when they are accompanied by sophisticated software that simplifies processes and eases the transition from specialists to generalists. It's a progression that's found its way into direct metal printing (DMP), also known as direct metal laser sintering (DMLS), for additive manufacturing.
Thinning the software herd.
Until recently, metal additive production was a complex, lengthy and sometimes frustrating trial-and-error process of preparing a file to print a part for demanding end-use applications.
Without the assistance of software like 3DXpert™, the printing preparation process requires importing and exporting among four or five different packages, all of which require some level of expertise to configure. Importing and exporting generally requires the STL format, which further complicates the workflow.
If the design incorporates complex lattice structures, job files can expand to hundreds of megabytes in size, slowing processing and import/export time. Each of the hand-offs leads the user down a one-way street: It is difficult to go back to any step of the process and make a change without starting over.
Integrated software such as 3DXpert includes all the preparation, print and post-processing steps in one package. It eliminates the STL file and instead communicates directly with the printer, including EOS, SLM and CLI formats as well as 3D Systems DMP printers. Data within 3DXpert, especially for parts with complex lattice structures, is significantly smaller than for an equivalent STL file.
Simplifying part supports.
One major issue with metal additive manufacturing is designing, programming, printing and removing support structures. To avoid the cost and time of redoing design and printing, users often over-support a part. This leads to other issues such as greater material costs and longer post-processing times.
Using an automated software helps engineers navigate the difficult landscape of applying support structures during the print process. 3DXpert is an all-encompassing package, helping users to define regions that require supports; to control the ability to tilt, offset and fragment supports to simplify removal and minimize material use. And this helps to define, save and reuse routines that automate support generation in different jobs.
Simulating before committing.
Another aid in getting a printed product right the first time is simulation. This takes the guesswork out of part support and orientation strategies.
The Build simulation module within 3DXpert predicts part deformation, cracking and other potential production issues. It gives engineers the ability to optimize their designs to use only the materials and supports that are absolutely necessary, while minimizing the risks of having to reprint. If a simulation reveals a problem, it is much easier, faster and cheaper to fix it within a digital environment and ensures your build will be successful.
Simulation is especially important for one-of-a-kind designs such as patient-specific medical implants and prototyping. This helps relieve designers with a deadline who can't rely on prior experience to get a design right the first time.
Proven production tool.
While comprehensive software is vital in helping to accelerate processes, reduce the learning curve, and eliminate mistakes, it's only as good as the hardware systems it drives. As with any good team, the sum should be greater than the parts.
In the case of 3D Systems’ direct metal printers, the hardware established itself many years ago, making the leap beyond prototyping to production parts to meet the most rigorous requirements.
Companies like Airbus have achieved major breakthroughs such as the first 3D printed radio frequency (RF) filter tested and validated for use in commercial telecommunications satellites.
In the medical field, individualized direct metal printed implants and devices have revolutionized surgery and treatment.
As with most technologies, the drive toward more widespread use of DMP centers on three key factors: cost, productivity and quality.
Assessing total cost of operation.
Much of the discussion on the cost of DMP centers on the initial purchase price of a production-ready 3D printer. But, that's just a small part of a much bigger picture. A better metric is total cost of operation (TCO), which helps buyers and owners determine the direct and indirect costs of a product or system over time.
At 3D Systems, we use key measures over time to assess and continuously improve TCO, including efficient use and re-use of powder material, durability during continuous use, speed of machine turnover, and time savings from reduced post-processing.
Productivity in the long run.
3D printing vendors often measure productivity as a one-off metric, as if 3D printer owners only do one job and then let the system gather dust for another 50 weeks out of the year.
At 3D Systems, we consider productivity a measure of time and cost savings over several years of continuous 24/7/365 service. DMP performance metrics are based on the time it takes for machine preparation, inerting (making a material non-flammable), deposition, scanning and building the part - not just a simple sample part, but many different representative parts over years of annual production.
Multiple measures of quality.
3D Systems measures quality in several ways, one of the most important of which is chemical composition of the printed material.
With many metal additive printers, oxygen present in the shielding atmosphere binds with the molten material to create various defects or changes in material structure. 3D Systems' DMP 320 printer removes excess oxygen in the shielding atmosphere and the powder bed by performing a series of vacuum cycles while preparing for production. This results in extremely low oxygen pick up in the printed material and powder, allowing for essentially unlimited reuse of metal powders.
Other measurable indicators of quality include:
- Material density and micro-structure
- Chemical composition and moisture within powders
- repeatable, stable mechanical properties of the printer during dozens of jobs over multiple years and
- Consistent part accuracy from different machines during jobs creating hundreds of parts over the course of several years
All of these measures factor into the design of the DMP 320 printer, which is proving itself within the most demanding production environments in aerospace, automotive, healthcare, durable goods and other industries.
Case in point.
Recently, Metal Technology Inc. (MTI) combined our advanced DMP printers and 3DXpert software to streamline the path from CAD to print to post-processing during the production of their 3D metal parts.
As a metal manufacturer serving a range of industries, including aerospace, defense, and medical, MTI was able to design and consolidate single, light-weight, integrated parts. The end result was better quality parts with longer life spans and lower costs.
Faster, more economical parts.
"The DMP Series printers allow us to produce end-use parts faster and more economically than ever before - in some cases as much as 10 times faster - and these parts are being used in some of the most demanding environments you can imagine," says Gary Cosmer, MTI's CEO. "3D printing the part enables us to include features and design parameters that could not be done with traditional methods."
Adding 3DXpert software to the mix has further increased productivity for MTI. The software's 3D Zoning capability has increased productivity by 40 percent by allowing MTI's engineers to define different printing strategies and layer thicknesses for different areas of a part.
3DXpert software also drastically reduced file processing time, according to Jason Stitzel, MTI's Director of Engineering.
"Before we used 3DXpert, running a complicated part through a slicing engine took close to 20 hours to process, slice, run the parameters and create a build file," says Stitzel. "With 3DXpert, we can do the same build in just four hours."
It takes two.
As the pace of DMP innovation continues to accelerate, it's good to keep in mind that technology rarely progresses from promising to essential without a harmonious union of hardware and software.
Ryan Kircher is Director of the 3D Systems Innovation Center in Denver, Colorado, where he leads a team that delivers application solutions to new and existing DMP customers. He has been active in the metal additive manufacturing industry for more than 10 years and was involved in delivering some of the first 3D-printed implantable medical devices to the U.S. market.