Page 33 - 3D Metal Printing Spring 2018

Question:
What are some tips for helping to achieve consistent quality in our builds, especially in critical production-part applications?
Answer:
As the additive-manufacturing (AM) industry moves more toward end-part production, especially of critical parts, the question of how to guarantee consis- tent quality while maintaining a positive business case becomes more relevant. The answer to that question can be found by learning from hundreds of years of manufacturing experience, and applying that to this newer technology.
The first element of a controlled process is locking down the variables as much as possible, using process controls and documentation (PCD). This can be challenging with a technology that undergoes change and improves at such a rapid pace as does AM, but at some point a line must be drawn at which point no changes can be implemented.
One key element of PCD is develop- ment of a plan to calibrate, verify and maintain the AM equipment to ensure consistent operation. Other elements include contamination control, powder handling, and configuration control of the machine hardware, operating soft- ware, and process-parameter themes.
Caitlin Oswald is an additive-manufacturing specialist with LAI International, Inc., a contract manufacturer of precision-engineered finished components and subassemblies for the aerospace, defense, energy, medical and industrial markets: coswald@laico.com; 612/300-8722; www.laico.com.
Please e-mail questions for Caitlin related to 3D metal-printing best practices for material selection, machine parameters, quality control, etc. to bkuvin@pma.org.
When demonstrating the ability to meet customer requirements, AM contract shops employ an array of conventional inspection techniques, including dimen- sional inspection through a CMM (shown) or struc- tured-light, 2D or 3D radiography, fluid-penetrant inspection, microstructural evaluation, and proof tests.
provide additional data that conventional manufacturing processes cannot provide, data that can be leveraged to offset some of the inspection needs.
For example, most AM equipment generates data prior to the build, during cali- bration and setup, as well as during and after the build. This data can come in the form of text, csv, image or PDF files, depending on the platform being used for pro- duction. The challenging question: How does the AM shop use all of this data?
First and foremost, shops should put a robust data-col- lection and storage system in place that can capture all of the data and correlate it back to a specific build, as well as to each part within a build. Then, shops can analyze the
Q&A 3D BY CAITLIN OSWALD
Q&A CAITLIN OSWALD
Additive Manufacturing
3DMPmag.com
SPRING 2018 • 3D METAL PRINTING | 31
With all of these elements under con- trol, an AM shop then can begin to focus on demonstrating consistent qual- ity to customers.
When demonstrating the ability to meet customer requirements, AM con- tract shops employ an array of conven- tional inspection techniques, including dimensional inspection through a CMM or structured-light, 2D or 3D radiogra- phy, fluid-penetrant inspection, microstructural evaluation and proof tests. However, these tests can prove expensive and time-consuming—cus- tomers considering AM for speed and cost benefits may find that inspection requirements can ruin the business case. Fortunately, though, AM processes can
collected data, in a meaningful way, using a handful of available tools, such as statistical-analysis software that can analyze large datasets and identify corre- lations. This exercise can be extremely useful and save an AM shop a lot of time and effort. Many companies also are developing their own analysis software specific to AM technologies.
At this point, the AM shop may have collected a lot of data and performed some amount of analysis. How, then, can it use the data to ensure consistent qual- ity, as well as save time and money? This exercise hinges on the analysis of key process variables (KPVs)—the character- istics of the process that directly impact build quality. A producer must combine