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Additive manufacturing (AM) has – and continues to – evolve dramatically in the sophistication of its technologies, processes, and materials. A broad range of industries ranging from aerospace to consumer products is using AM to refine the development and production of products. The explosive growth in AM and how practitioners are deploying it is supported by a wide number of metrics, including the 20 fold gown in AM-related patents and the astounding growth in the sale of industrial AM systems over the past 4 years.
Fueled by growth of Industry 4.0 and the digital thread, AM has emerged as a catalyst in reshaping underlying assumptions about product complexity, supply chain logistics, and possibly even the manufacturing business model itself.
DEFINITION – Industry 4.0 : Industry 4.0 is a reference to what might otherwise be called the the Fourth Industrial Revolution. This is the ongoing automation of traditional manufacturing and industrial practices, using modern smart technology. Large-scale machine-to-machine communication (M2M) and the internet of things (IoT) are integrated for increased automation, improved communication and self-monitoring, and production of smart machines that can analyze and diagnose issues without the need for human intervention.
DEFINITION – Digital Thread: Tech Target defines the digital thread as “a communication framework that connects traditionally siloed elements in manufacturing processes and provides an integrated view of an asset throughout the manufacturing lifecycle.”
However remarkable the growth thus far, challenges lie on the horizon that if unaddressed could impede broader implementation of AM in industrial settings. And among those challenges, the lack of a widely accepted comprehensive set of technical standards within AM looms large.
Why do standards matter?
Standards are necessary to ensure that such rules of the game are established, adhered to, and respected by all parties. Standards have been a fundamental part of the manufacturing background for decades, they are essential as they outline the parameters that must be met to deliver a quality product.
It’s no different for AM
In many ways, AM is a ‘democratization’ of the production process. A digital file designed by one person can be modified and produced differently by a hundred different people by changing any number of settings used in the items creation. Given the capacity for endless variations, standards become all the more important because they define quality, provide benchmarks and best practices.
Quality end-use, functional parts are already being produced via AM but widely adopted standards would help the quality over longer production runs. Ongoing efforts to establish AM standards should define the requirements for AM production, helping to enhance operational consistency and ensure quality as production and market adoption grows. As standards help assure quality for a larger volume of parts, the AM industry can scale, reach new levels of efficiency, and garner additional benefits from AM use.
Quality standards can also be particularly important for AM because there are arguably more factors to consider than for conventional manufacturing; now, digital design standards, interoperability standards, layer-by-layer material/build process parameters, microstructure strength, porosity, and post-processing/curing standards, among others, should all be considered. In a complex industry with a host of variables at play, AM standards should provide the “guidebook” for implementation.
Below is a shortlist of potential benefits that can arise from the application of standards to the use of AM:
- Risk Mitigation: While standards will not mitigate all risks associated with any manufacturing process, adopting them can mitigate and control risks in ways that cross many domains such as worker safety, security of information, intellectual property, the manufacturing process, and supply chain management.
- Improved Repeatability: In the highly customizable environment represented by AM, standards can define key parameters — materials, print process, material storage, etc. In effect, standards should provide a sense of predictability and repeatability within the AM ecosystem.
- Quality Benchmarks: Quality is explicitly “the use of a standard against which other things of similar kind are compared.” As such, standards provide the benchmark criteria against which the quality of a company’s AM process—and products of that process—can be compared. A primary aim of standards should be ensure that designs, printers, and settings achieve a desired quantifiable and quality outcome.
- Greater Efficiencies: By virtue of helping to accomplish the first three benefits, AM standards may also provide an opportunity for companies to focus their processes and practices in a more optimally efficient and less wasteful way. For example, the use of a standard output file format for the instructions needed to print a part would reduce the need to develop a custom file format and, in the process, enable greater interoperability—and efficiency—among different players across the AM ecosystem. This can also reduce the need for rework during production, thus again reducing waste and improving return.
That seems like a big list of features and you would be right to ask…how exactly?
- Part Design: AM enables the creation of parts that can exceed traditional design limitations, even mimicking a variety of organically shaped, nongeometric bio-inspired design. These new designs allow parts to exceed previous constraints and demonstrate increased feats in strength, weight reduction, and even product performance. But in order to allow a quality assurance process to gauge whether the production is being controlled, for instance, traditional standards may not suffice.
Revised and new standards have begun to evolve to bridge industry specific gaps to reflect design within the AM ecosystem.
- Production and Materials: Many traditional manufacturing standards are well established and may be applied to AM as well. However, there are areas where additional research is required address uncontrolled variables introduced by AM production processes. For instance, powdered bed fusion metal printing processes may trap miniscule amounts of gases within the printed material creating potential anomalies in the final part. Analysis and the introduction of production standards would be beneficial to account for such anomalies.
Since materials used in AM are commonly found in traditional manufacturing processes, standards related to storage, handling, and transportation are relatively well articulated. It is still important consider what the printing process itself does to the material, and how this may be used to improve the product. For example, AM may introduce inherent molecular deformations which can actually prove beneficial in high-stress end-use cases where temperature, pressure, or material can actually be balanced out by the material stresses.
This would require standards against which materials, printing processes, and inherent material stresses can be judged.
- Digital Thread: Applying standards on the data produced from the AM processes is the final and perhaps most challenging area. Our digital world is developing at an exponential pace as data formats and processing requirements seem to evolve every few years. With the “thread” approach to manufacturing becoming increasingly pervasive, it could be almost essential to consider the longevity of the AM digital presence and how rapidly anything we produce digitally will likely no longer be transferrable to the next file format.
While standards such as the .STL—a standard format for sending instructions to the 3D printer— exist and are widely applied today, there is an ever-present desire for something better. A major challenge facing the application of data standards is how to build in longevity into the standard. Thus, AM should begin to invest effort in producing data and information standards that can be easily updated and copied to the next generation of hardware and computers.
Recognizing your organization’s need to identifying
- Needs Assessment: This first step is likely the most important. Define your parameters and conceptual benchmarks and steps in the process where the company needs a standard. This includes determining your expectation of success.
- Determine the Variables: As an example, determine printer settings available, then print using each variable and measure the outcome to understand the impact of the setting on the part printed.
- Data Collection: Determine how you will measure the results of each pass of your process and variable settings. An example might be to identify how you will measure if your additively manufactured part met reliability requirements or how you plan to measure the humidity inside a printer during operation.
- Experiment: Run your experiment several times, testing each variable in isolation, and measure your results.
- Observe and Analyze: Analyze the data collected to see which variable settings provide the best outcome or best achieves your AM objectives. The best settings may likely become your new standard where industry standards do not exist.
Partial List of Existing Standards
Despite its relative newcomer status on the manufacturing stage, AM has garnered a fair amount of attention from standards organizations globally and a fair amount of work has already been done to bridge the gap in standards. Below is a partial list of of AM related standards and the organizations that have fostered them. Both the ASTM (F42) and ISO (ISO/TC 261) have formed committees that meet regularly to review and discuss modifications and additions to additive standards.
- ISO/ASTM 52900 – Additive Manufacturing General Principles: co-publication between the American Standards for Technology and Materials and the International Organization for Standardization replaces the now cancelled ASTM F2792 Standard Terminology for Additive Manufacturing Technologies and serves as the basis for subsequent standards development.
- ISO/ASTM 52901: 2017 – Additive Manufacturing General Principles – Requirements for Purchased AM Parts: gives guidelines for the elements to be exchanged between the customer and the part provider at the time of the order, including the customer order information, part definition data, feedstock requirements, final part characteristics and properties, inspection requirements and part acceptance methods.
- ISO/ASTM 52910: 2018 – Guidelines for Design for AM – This document gives requirements, guidelines and recommendations for using additive manufacturing (AM) in product design.
- ISO/ASTM 52921: 2013 – Standard Terminology for Additive Manufacturing, Coordinate Systems and Test Methodologies – includes terms, definitions of terms, descriptions of terms, nomenclature, and acronyms associated with coordinate systems and testing methodologies for additive manufacturing (AM) technologies in an effort to standardize terminology used by AM users, producers, researchers, educators, press/media, and others, particularly when reporting results from testing of parts made on AM systems.
- ASTM F3049 – 14 – Standard Guide for Characterizing Properties of Metal Powders Used for Additive Manufacturing Processes
- ASTM F3122 – 14 – Standard Guide for Evaluating Mechanical Properties of Metal Materials Made via Additive Manufacturing Processes
- AWS D20.1/D20.1M:2019 – American Welding Society Specification for Fabrication of Metal Components Using Additive Manufacturing – This specification provides the general requirements for fabrication of metal components using additive manufacturing. It provides guidance for the interaction between the Engineer and the Contractor. It includes the design, qualification, fabrication, inspection, and acceptance of additively manufactured components. A commentary for the specification is included.
- DNVGL-ST-B203 – Additive Manufacturing of Metal Parts – This is the first Standard to provide an internationally accepted framework for producing and using high quality additively manufactured metal parts for the oil & gas, maritime and related industries. It introduces approaches to manage the quality of additively manufactured metal parts, with each approach adapted based on the criticality of a part’s function. This helps to ensure predictability in the supply chain, reducing lead time and cost.
- FDA – Technical Considerations for Additive Manufactured Medical Devices – Guidance for Industry and Food and Drug Administration Staff