Fracture Toughness Measurements of Powder Bed EBM Additive and Subtractive (Hybrid) Titanium Alloy Ti6Al4V

Abstract

Metal additive manufacturing (AM) is a fast growing field of technology, and electron beam melting is one of the few processes capable of producing functional metallic parts. AM method is a layer by layer manufacturing methodology which allows for building of nearly any complicated geometric design. Additionally, additive manufacturing offers customization and has the potential to drastically reduce material waste. However, there are some significant problems that must be addressed for metal additive manufacturing to become more widespread. Ensuring that mechanical performance requirements can be met by EBM-produced parts is essential. The mechanical properties of Ti6Al4V EBM are largely explored under monotonic stress in current metal AM research, with limited research on fracture resistance. Fracture toughness is a key property in damage tolerance and is the primary metric to define the resistance to fracture of a material. To assess the relative impacts of part position, geometry, and proximity on the metal's fracture toughness properties, a design of experiments technique was used. The radial distance from the center of the build plate, as well as the thickness of the components and height had significant influence on the fracture toughness properties. The maximum results for fracture toughness can be obtained with an increase in height and a decrease in radial distance on the build plate. Even this understanding is crucial in advancing the effectiveness of EBM additive manufacturing for stress-sensitive components in aerospace and beyond. Nonetheless, additional efforts are required to improve the technology to the point where it can be adopted into aerospace manufacturing as a dependable manufacturing process.