Controlling the microstructure of GRCop 42 in the fabrication of unsupported overhang parts using the Laser Powder Bed Fusion process
Controlling the microstructure of GRCop 42 in the fabrication of unsupported overhang parts using the Laser Powder Bed Fusion process
Monday, October 20, 2025: 12:00 PM
Additive Manufacturing (AM) has quickly revolutionized the industrial and manufacturing
domain. It has several applications including but not limited to aerospace and defense
to rapid prototyping. AM enables the manufacture of complex, unique application
specific parts and structures. The parts built can have multiple degrees of freedom not
capable with traditional manufacturing methods which eliminates many connections and
subsequently possible failure points. These waveguides may have tooling features
which cannot be supported such as internal tooling parts. As a result various methods of
removing these supports such as chemical etching or mechanical abrasion can reduce
the structural integrity. Although AM waveguides have been produced, limited research
has been done to improve the surface roughness and finish especially on parts with
complex internal features and overhangs. This becomes an issue when working with
higher frequency waves such as high power radio frequency (RF) and microwaves
which hinders the efficiency.
When constructing these parts the lower thermal conductivity relative to the finished part
which acts as an insulator makes it challenging to have downskin parts with a high
surface quality and low average surface roughness. This is due to limited heat
dissipation of the melted overhang on the downskin. As the build angle from the
horizontal is decreased and approaches , there is an increased residual stress
accumulation due to the rapid remelting and solidification of the layers. This results in
warping and can lead to failure of the build.
In this approach, we are investigating how the surface quality of unsupported parts and
features can be improved by controlling various building parameters. By altering these
parameters, grain growth and subsequently the mechanical properties can be
controlled. As a result the and precipitates can be evenly distributed especially in these
downskin regions to prevent localized deformation of the finished parts.
domain. It has several applications including but not limited to aerospace and defense
to rapid prototyping. AM enables the manufacture of complex, unique application
specific parts and structures. The parts built can have multiple degrees of freedom not
capable with traditional manufacturing methods which eliminates many connections and
subsequently possible failure points. These waveguides may have tooling features
which cannot be supported such as internal tooling parts. As a result various methods of
removing these supports such as chemical etching or mechanical abrasion can reduce
the structural integrity. Although AM waveguides have been produced, limited research
has been done to improve the surface roughness and finish especially on parts with
complex internal features and overhangs. This becomes an issue when working with
higher frequency waves such as high power radio frequency (RF) and microwaves
which hinders the efficiency.
When constructing these parts the lower thermal conductivity relative to the finished part
which acts as an insulator makes it challenging to have downskin parts with a high
surface quality and low average surface roughness. This is due to limited heat
dissipation of the melted overhang on the downskin. As the build angle from the
horizontal is decreased and approaches , there is an increased residual stress
accumulation due to the rapid remelting and solidification of the layers. This results in
warping and can lead to failure of the build.
In this approach, we are investigating how the surface quality of unsupported parts and
features can be improved by controlling various building parameters. By altering these
parameters, grain growth and subsequently the mechanical properties can be
controlled. As a result the and precipitates can be evenly distributed especially in these
downskin regions to prevent localized deformation of the finished parts.