Developing Processing Parameters and Characterizing Microstructure and Properties of an Additively Manufactured FeCrMoBC Metallic Glass Forming Alloy

Abstract

Powder bed fusion (PBF) processing parameters are developed for a FeCrMoBC glass‐forming alloy. Although bulk metallic glass parts are successfully fabricated using additive manufacturing, the porosity is too high for imparting good mechanical properties. The processing is tuned to create a fully‐dense, dendrite‐reinforced metal‐matrix composite with low hardness and high indentation fracture toughness. Microstructures and properties of the printed alloy are compared to bulk amorphous samples made through thermal spray additive manufacturing (TSAM). The work shows that printing glass‐forming alloys can result in tunable properties based on the cooling rate, porosity, and composite microstructures.

Towards additively manufacturing excavating tools for future robotic space exploration

“…34 Depending on the geometry of the excavating tool and the forces on the blade, even brittle materials have been shown to survive cutting the simulant. The work shown here motivates the development of BMG alloys in other systems, like Fe, that have been shown to have hardness over 1000 H V. 37 Lastly, this work has demonstrated the potential of using an excavating tool to interrogate the mechanical properties and morphology of an unknown simulant. By measuring the forces and slopes of the force feedback from the excavating tool, it becomes possible to learn about the hardness and homogeneity of the simulant.…”

“…Previous work by NASA JPL had shown that the application of this coating through high velocity oxygen fuel thermal spraying produced a durable coating on an aluminum rover wheel. 37 It was hoped that a similar coating might provide a hardfacing to the soft aluminum blade sufficiently robust to allow for cutting through the simulant and the smaller size of the blade was intended to reduce bending loads on the softer aluminum Ti-6Al-4 V was also printed in the 80 mm geometry to provide a direct comparison between the large blade design and the small one printed from the same alloy.…”

Thermophysical Properties of an Fe57.75Ni19.25Mo10C5B8 Glass‐Forming Alloy Measured in Microgravity

“…[ 10–13 ] Previously, it was already demonstrated, that by, e.g., powder bed fusion (PBF), thermal spray additive manufacturing (TSAM), and direct energy deposition (DED) of FeCrMoCB a large variety of microstructures can be achieved: fully amorphous, dendrite‐reinforced metal matrix composites, and fully crystalline. [ 14,15 ] Despite these developments, Fe‐based metallic glasses have not found widespread use outside of coatings due to their exceptionally low fracture toughness in large glass‐forming compositions and their reliance on volatile phosphorous in their tougher compositions. Tough Fe‐based metallic glasses have been previously demonstrated in the FeNiBX system, but these are only accessible in the amorphous state through ultrarapid cooling.…”

“…To avoid a time consuming, completely empirical process development for an additive manufacturing process, [ 15 ] numerical models of the fabrication process have nowadays become an essential instrument. Using the correct simulation models and precise thermophysical property data, the temperature distribution and history, fluid flows in the melt, porosity and other defect formation, as well as the formation of thermal stresses during the solidification in the additive manufacturing process can be predicted.…”

Estimation of Residual Stress in Selective Laser Melting of a Zr-Based Amorphous Alloy

“…With respect to 3D printing amorphous alloys, the previous literature focused only on the possibility of 3D printing amorphous alloys [ 30 , 31 ], the effect of laser processing parameters on microstructure evolution [ 12 , 32 , 33 ], thermal stress induced micro-cracks [ 13 , 34 , 35 ] and possible mechanical properties [ 13 , 15 , 16 ]. The investigation of residual stress in 3D printed amorphous alloys is actually scarce, and the detailed distribution remains unclear, which is deleterious for controlling the dimensional accuracy and preventing premature fatigue failure of the 3D printed components.…”