Certifying a system containing AM parts from engineering materials requires an understanding of the properties of the material as a function of composition, processing, and environmental effects on the part and the material it is made from. As we now begin to cover qualification, it is important to keep in mind that the primary goal of qualification is demonstrating that the production system (factory, personnel, AM machines, post-processing, feedstock, and quality assurance measures) is capable of repeatedly and reliably producing AM parts whose properties are consistent with those used to design the system.
Certification ensures a component meets specified requirements, which are defined according to industry, material, regulatory agencies, and other factors. The process begins with defining system requirements by stakeholders (e.g., customers, users, and regulators) and proceeds through design, manufacturing, testing, and certification phases. Certification includes system, part, operator, and material certifications.
System certification involves extensive testing (e.g., flight tests for aircraft) and analysis to validate performance. For parts like AM components, both material strength and design efficiency must be assessed. Part certification is more frequent, verifying compliance with technical and manufacturing standards through a Certificate of Conformance.
Operator certification ensures skilled personnel produce quality parts, requiring training and proficiency evaluations. Material certification ensures feedstocks meet technical specifications, with standards varying from public to proprietary requirements.
Certifying systems with engineered materials requires comprehensive property knowledge, including strength, reliability, and environmental effects. Methodologies like MMPDS provide statistical design values for materials, critical for safety and performance.
Nondestructive testing (NDT), essential in high-stakes industries, includes methods like radiography, ultrasonics, and eddy-current inspection, identifying defects without damaging components. Emerging technologies like in-situ NDT integrate real-time monitoring during AM processes, enhancing defect detection and system reliability. Combining design, analysis, and NDT ensures robust certification practices, especially in evolving fields like AM.