Direct Metal Deposition of Satellited Ti‐15Mo: Microstructure and Mechanical Properties

Abstract

Satelliting has been shown to be an excellent method for rapid and low cost preparation of feedstock for metal‐based additive manufacturing. In this study, a biomedical titanium alloy Ti‐15Mo is produced by direct metal deposition (DMD) using the satelliting powder preparation method. The microstructure and mechanical properties are then explored. The microstructure in the DMD Ti‐15Mo sample consists primarily of fine equiaxed grains and near‐equiaxed grains. The cellular substructures are present at the bottom of each deposited layer while there are no obvious substructures in the upper region of each deposited layer. The formation of the morphologies of prior β grains is explained by combining the analysis of the nucleation effect of the partially un‐melted particles, while the substructure formation can be explained using the solidification and thermal cycling analysis during the DMD process. The compression test results show excellent compressive properties with a high strength of 1764 MPa and low compressive elastic modulus of 28.4 GPa.

Solidification Effect on the Microstructure and Mechanism of Laser‐Solid‐Forming‐Produced Flame‐Resistant Ti–35V–15Cr Alloy

“…Furthermore, the solidification parameters at the tail of the molten pool in the 8th layer of as‐deposited sample were labeled in the CET curve with the assumption that the solidification velocity V equals to the scanning speed v = 10 mm s −1 at the tail of the molten pool, as shown in Figure . From the analysis in previous work, which demonstrated the relationship between the solidification parameters and the thickness of the equiaxed grains layer in each deposited layer, the equiaxed grains layer in each deposited layer of LSF‐produced Ti–35V–15Cr thin‐wall sample would be much thicker than that in block counterpart . In addition, the thermal behavior of the solid–liquid interface front in the actual molten pool would be affected by some factors, such as melting of powder particles, convection of liquid phase and inhomogeneity of composition.…”

“…From the analysis in previous work, which demonstrated the relationship between the solidification parameters and the thickness of the equiaxed grains layer in each deposited layer, the equiaxed grains layer in each deposited layer of LSF-produced Ti-35V-15Cr thinwall sample would be much thicker than that in block counterpart. [35] In addition, the thermal behavior of the solid-liquid interface front in the actual molten pool would be affected by some factors, such as melting of powder particles, convection of liquid phase and inhomogeneity of composition. This makes the solidification conditions at the front of solid-liquid interface disturbed, which causes the CET to actually occur within the specific depth range of molten pool.…”

Additive Manufacturing of Titanium Alloys: Processability, Properties, and Applications

“…Additionally, the Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si alloy exhibited a better tensile strength than Ti6Al4V. [155] Copyright 2019, John Wiley and Sons Inc.…”

“…A schematic of the formation of partially unmelted Mo particles and the morphology of prior β grains is presented in Figure . [ 155 ] Compared to vertical surfaces, the double oxide layer passivation created higher corrosion resistance on horizontal surfaces. Additionally, due to the low thermal gradients, the vertical specimens exhibited homogenous and more significant apatite formation due to higher surface topographic features and the type of surface morphology formed.…”

“…Schematic showing the formation of unmelted Mo particles and the morphology of prior β grains. Reproduced with permission [155]. Copyright 2019, John Wiley and Sons Inc.…”