In this month’s “Six Questions” feature, we’re talking with Dr. Kahlid Rafi about the new UL Metals Validation Program – a collaborative program between UL and Singapore’s Advanced Remanufacturing and Technology Centre (ARTC), focused on the verification and certification of metal powders for Additive Manufacturing (AM) technologies.
#1 What were the drivers behind developing an AM validation program for metal powders?
There are a few specific market and product (material) related factors we had to consider. First, among the different AM technologies, metal powder-based technologies make-up a significant portion of the market. Moreover, the demand for these “metal machines” is continuing to grow.
Second, as AM technology matures toward an acceptable manufacturing process, feedstock material control becomes a requirement to ensure quality of the final part. With AM technologies, the characteristics of the final part are determined by a combination of material and the process.
Third, more and more metal powder manufacturers are entering the market to meet the growing demand and third-party assurance of material quality characteristics will increase confidence among end-users.
#2 What key activities and research were needed to establish this sort of a program?
The UL Metals Validation Program is an outcome of 2 years of industry research with analysis and inputs from AM industry and research institutes. You see, AM technology is new from an industry application perspective. Currently, the need for AM-specific test methods is not realized, and hence, the methods are not yet developed. Therefore, careful selection of test methods from the existing battery of tests and development of test protocols are needed. For instance, some of the existing test methods can be directly applied for AM, while some test methods can be used with some modifications, and some other test methods cannot be used at all.
Since AM is a unique manufacturing process, research is needed to identify and establish material properties which are critical to application requirements rather than trying to match the characteristics with conventional processes, such as casting, molding, or machining. Some of the key activities included identification of existing standards, which are relevant and can be used for testing the parts produced by AM, association with standard development organizations, deep involvement in the standard development process, and interactions with industry stakeholders and research institutes to understand the gaps and their requirements. We also developed technical guidance documents and validated the guidance documents with industry pilot projects. It was a significant, and thorough, effort.
#3 What are the key industry challenges manufacturers are experiencing in bringing AM metal parts to production?
Challenges exist from the design to the final stage of post-processing. Different industry players tackle the challenges in different ways, often using procedures developed internally. This is good to drive the technology at a faster pace during its infancy, but in the long run, a standardized approach is needed. That standard approach is currently lacking.
Another challenge is the need for established standards - which are a sign of maturity for any new technology. For AM, though efforts are underway, there is still a long way to go in the development of a full suite of AM standards. This limits the certification of parts produced by AM. As a result, regulatory pathways are still not clear in the instances where AM is used to produce a component or a fully functional part.
Demonstrating the suitability of an AM metal component to meet the functional requirements is also a challenge. The lack of historic data makes the process more difficult in predicting the product life cycle and potential failure modes.
Stack these on top of process instability, interoperability between multiple machine platforms, real-time monitoring and in-situ process control, anisotropy, and proper selection of material and process…and you have a significant list of challenges to overcome. However, that’s where our program can help.
#4 Who are UL and ARTC targeting for the program? Where can the great benefit be realized?
The UL Metals Validation Program is designed for relevant AM stakeholders, such as metal powder manufacturers, contract manufacturers, manufactures who use AM in their manufacturing ecosystem, and AM software solution providers. We’ve found material properties presented in data sheets usually represent only the best case scenarios. This program will give more detailed and realistic information over a range of conditions.
The real benefit of this program is that stakeholders can position themselves in the AM marketplace with trust and confidence in their product and services. In addition, a third-party validated AM material and process will gain more visibility and credibility. As the technology develops further, the early adaptors of this program need only minimal effort to stay relevant with a validated material and process.
#5 What differentiation will UL and ARTC bring to the space?
Over the years, UL has demonstrated trust and confidence in various industry sectors through its certification programs. In the past four years, UL has developed the expertise to support the AM industry in terms of safety and quality in all stages of the process chain.
As a research institute focused on Advanced Manufacturing, ARTC has emerged as a center of excellence in performing cutting edge technology research with a strong focus on Additive Manufacturing. A wide range of metal AM machines and supporting equipment with a veteran team of AM engineering experts makes ARTC the right place to perform research and testing in the AM space.
Together, UL and ARTC can bring value to the AM industry by covering the entire AM production spectrum and providing a one-stop solution with integrated services.
#6 Where do you see the program in the next 3-5 years?
Metal AM is expected to grow exponentially over that timeframe. Therefore, the UL Metals Validation Program will also stay abreast with the growth trend. We currently leverage existing standards and industry best practices and will incorporate new standards as and when they are introduced. Simply put, any changes in the metal AM market will be reflected in the execution of the Metals Validation Program. We designed it that way.
We believe this program will develop as a robust and a well-recognized program across the industry and with the regulatory bodies. And, in a span of 5-10 years, this will become an industry norm in AM, similar to other UL AM programs.
About Dr. Khalid Rafi
Joining UL in 2015, Dr. Khalid Rafi is responsible for the development of AM materials validation and process validation programs at UL’s Global AM Center of Excellence in Singapore. Leveraging his 14 years of experience in teaching and research, Rafi is also engaged in the development and delivery of UL’s AM training program.
Rafi is recognized as one of the few established metallurgists within the AM industry. His research focuses on process optimization, materials characterization and developing structure-property correlations for metallic parts produced using additive manufacturing techniques including selective laser melting (SLM), electron beam melting (EBM) and ultrasonic consolidation (UC).
Rafi holds a Masters and PhD in Materials and Metallurgical Engineering from the Indian Institute of Technology, Madras, India and has earned a post-doctoral fellowship from the University of Louisville, Kentucky, USA and Nanyang Technological University, Singapore.
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