Friction Stir Additive Manufacturing—A Review
21
Fig. 5 Friction deposition technique employed by aeroprobe corporation. a The schematic of the
process of friction deposition [69], b the aeroprobe nozzle that employs a continuous feeding system
with a self-reacting tool [69, 71, 72]
tool, was developed by Aeroprobe corporation, a company specializing in frictionbased deposition [67] which was also the first one to develop the commercialized
technology based on this process [68, 69]. Their patented technology of friction stir
fabrication (FSF), which was rebranded under the name of MELD technology [70],
can be used for additive manufacturing, coating and repairing of varied industrial
applications.
As shown in Fig. 5a, the stirring tool rotates and translates relative to the substrate.
The stirring tool, as shown in Fig. 5b, is a hollow cylinder with a throat that feeds
the coating material to the surface of the substrate through an auger-shaped plunging
tool which moves relative to the sleeve of the stirring tool.
The process of depositing the material is completed by plastically deforming
material from the tool and spreading it on the surface of the substrate through the
translative motion. The stirring tool comprises a shoulder [72] that moves relative
to the surface of the substrate. The shoulder is used for trapping and shearing the
material below. The material is subjected to the frictional heat and compressive load
against the substrate. As the load increases, more material is deformed. This material
is trapped below the shoulder and is sheared across the substrate surface where it has
to be deposited. The feed material is in the form of powder or pellet for continuous
feed applications through this technology.
Notably, this technology is the answer to the lower deposition rates of friction
surfacing process. The deposition rate on the substrate can be controlled by the
varying the parameters of the auger screw like the threads or the relative velocity
between the auger and the screw [69]. This technology can produce high-strength
welds and coatings. The mechanical properties of the fabricated structures match with
that of the base metal and they also retain a wrought microstructure with negligible
porosity.
21
Fig. 5 Friction deposition technique employed by aeroprobe corporation. a The schematic of the
process of friction deposition [69], b the aeroprobe nozzle that employs a continuous feeding system
with a self-reacting tool [69, 71, 72]
tool, was developed by Aeroprobe corporation, a company specializing in frictionbased deposition [67] which was also the first one to develop the commercialized
technology based on this process [68, 69]. Their patented technology of friction stir
fabrication (FSF), which was rebranded under the name of MELD technology [70],
can be used for additive manufacturing, coating and repairing of varied industrial
applications.
As shown in Fig. 5a, the stirring tool rotates and translates relative to the substrate.
The stirring tool, as shown in Fig. 5b, is a hollow cylinder with a throat that feeds
the coating material to the surface of the substrate through an auger-shaped plunging
tool which moves relative to the sleeve of the stirring tool.
The process of depositing the material is completed by plastically deforming
material from the tool and spreading it on the surface of the substrate through the
translative motion. The stirring tool comprises a shoulder [72] that moves relative
to the surface of the substrate. The shoulder is used for trapping and shearing the
material below. The material is subjected to the frictional heat and compressive load
against the substrate. As the load increases, more material is deformed. This material
is trapped below the shoulder and is sheared across the substrate surface where it has
to be deposited. The feed material is in the form of powder or pellet for continuous
feed applications through this technology.
Notably, this technology is the answer to the lower deposition rates of friction
surfacing process. The deposition rate on the substrate can be controlled by the
varying the parameters of the auger screw like the threads or the relative velocity
between the auger and the screw [69]. This technology can produce high-strength
welds and coatings. The mechanical properties of the fabricated structures match with
that of the base metal and they also retain a wrought microstructure with negligible
porosity.