DEVELOPMENT OF POST-PROCESSING TECHNOLOGY FOR ADDITIVE MANUFACTURED COMPONENT

Abstract

ABSTRACT OF THE INVENTION: The present innovation offers a technological development for the post-processing of an additive manufactured metallic component. An automated pulsed gas tungsten arc welding - based additive manufacturing technology is employed for the production of metallic component 10 (108). Common problems associated with additive manufacturing techniques encompass cracking, permeability, depletion of alloying elements, variable surface properties, and residual stress arising from temperature variations during the layer-by-layer deposition ( 1 07) process. To mitigate the aforementioned faults in the AM metal alloy (110). Various post-processing treatments have been employed. The current innovation introduces an innovative post-processing 15 technology known as prestressed shot peening or stress peening. This post-processing technology eventually resulting in superior product quality.

Specification

DESCRIPTION:
[0001) The current .innovation pertains to enhancements in post-processing technology for
additively manufactured components. The present development pertains to the impact of postprocessing
on preventing the segregation of Mo-rich precipitation, enhancing surface and
5 mechanical characteristics, and eliminating residual stress and cracks in the 3D printed metal
components. The innovation related to the additive manufacturing of superalloy. The current
technology specifically pertains to a pulsed gas tungsten arc welding-based additive
manufacturing technique intended for the fabrication of superalloy and the.subsequent execution
of novel post-processing technology. aimed at preventing segregation, enhancing surface and
I 0 mechanical properties, and reducing residual stress and fractures in the metallic alloy. This
innovation additionally offers finite element modelling for predicting residual stress distribution
in both as-fabricated circumstances and different post-processing scenarios.
15
PRIOR ART AND BACKGROUD OF THE INVENTION:
[0002) Additive manufacturing (AM) is a cutting-edge process employing to produce intricately
built components, often referred to as rapid manufacturing and three-dimensional (3D) printing.
Metal additive manufacturing (MAM) is the foremost rising manufacturing process of the
present day. MAM is used across several sectors, includes aerospace; automobiles health care,
chemical processing, and maritime industries. In metal-based additive manufacturing, the use of
an actual heat source (such as laser, arc, or electron beam) to selectively melting alloys wire or
20 pow:der leads to solidifying, representing a significant improvement comparing to traditional
castings methods.
[0003) MAM has two pnmary categories: powder bed fusion (PBF) and directed energy
deposition (OED). In contrast to PBF, OED offers an elevated build rate, between 50 to 130
g/min, while laser-based PBF AM processes typically achieve rates of 2-10 g/min. Arc-based
25 OED demonstrates a much higher material deposition rate and is more appropriate to produce
huge metal components. Wire arc additive manufacturing (W AAM) is a promising directed
energy deposition method. A metal wire feedstock and electrical arc energy source enable layerby-
layer deposition. The W AAM process offers low initial investment, lower material costs,
faster deposition (up to 9 kg h-1 ), and exceptional industrial flexibility.
30 [0004) WAAM technologies employs Gas Tungsten Arc Welding (GTAW), Gas Metal Arc
Welding (GMAW), or Plasma Arc Welding (PAW) processes for components fabrication. The
W AAM process has now been used to fabricate various metallic components, such as titanium,
~ aluminium, nickel-based superalloys, and functionally graded metals .. ~he AM research group primarily focuses on nickel-based superalloys and titanium. Their remarkable strength at
elevated temperatures and extensive variety of applications are the primary reasons. Typical
defects observed with additive manufacturing methods include cracking, permeability, depletion
of alloying elements, inconsistent surface characteristics, and residual stress resulting from
5 temperature fluctuations during the layer-by-layer deposition process. To mitigate faults arising
from the additive manufacturing process, it is essential to perform post-processing treatments.
[0005] In CN115156551B, the authors devised multi wire synchronised AM to mitigate faults.
The invention addresses issues such as particles clustering and permeability defects that
commonly arise during the arc material-increasingmethod. US9233432B2 and US201401334A1
·I 0 describe concepts for a dual-electrode torch, using two distinct electrical sources for power
delivery. Two arcs are linked at one end to a single electrode and diverge at the other end
towards the second electrode and the workpiece. The reported GT A W arc is traditional and lacks
energy concentration methods. The technology described in EP4196307 A2 employs a method
distinguished by low thermal input, reduced distortion, minimal spatter, and relatively high
15 deposition rates in laser-GMA W hybrid additive manufacturing technique.
[0006] CN107671288B discloses an AM apparatus and methodology. The authors indicated that
the post-processing the component is utilised to address and rectify the damaged regions of the
material in a designated post-processing technology aimed at defect elimination. This postprocessing
technology encompasses several steps, including a minimum one of mechanical
20 rolling, laser shock or shot peening, and .friction stir processing. Inv~ntion ES2961482T3
. .
involves additive manufacturing. The authors discuss powder-based AM polymer component
post-processing. Thus, AM components are generally post-processed to smooth down their rough
exteriors and remove support structures. Main post-processing categories are primary and
secondary. Primary post-processing often includes all AM components' necessary steps for
25 deployment in any application. Secondary post-processing includes polishing the component for
look and/or functionality. 201010147632.2 uses plasma arc AM and mechanical rolling to
increase stress and deformation while precisely managing the deposit's surface. The approach is
cost-effective but does not strengthen materials. The investigators stated that short pulse laser
shock peening technology may solidify a layer, induce residual compressive stresses, and
30 enhance 3D printed material surface qualities.
[0007] Consequently, there is a perceived necessity for enhanced post-processing treatments for
additive manufactured components to prevent elemental segregation, enhance surface and
mechanical properties, and alleviate residual stresses and cracking tendencies in manufactured
components, as elaborated upon below.



OBJECTIVE:
[0008] The primary aim of this innovation is to get a flawless end product produced by a pulsed
arc-based additive manufacturing technology. This innovation developed a post-processing
technology to improve the material's characteristics. The post-processing technology include shot
5 peening and prestressed shot peening or stress peening. The manufactured material undergoes
treatment with cast steel shots and is prestressed by four-point bending, during which shot
peening is executed on the prestressed sample. The defects were identified by several
metallurgical (surface properties, SEM/EDS) and mechanical (residual stress, tensile)
characteristics. Finally, this innovation additionally offers finite element modelling for predicting
10 residual stress distribution in both as fabricated and varied post-processed circumstances. This
invention proposes optimal post-processing technology for achieving enhanced material
qualities.






CLAIM:
WE Claim,
I. A pulsed arc-based additive manufacturing system is employed to fabricate threedimensional
metal component. This system includes:
• Automated gas tungsten arc welding equipment with a welding torch (102) and a
deposition unit (101) utilizing a pulsing current power source (103) to reduce
thermal input and accelerate cooling rates, enhancing metal alloy quality.
• The automated deposition unit (101) improves oversight and accuracy in
production, resulting in increased efficiency. Although pulsed arc-based additive
manufacturing reduces defects compared to conventional methods, postprocessing
is essential to achieve defect-free components for mission-critical
applications.
• The present invention incorporates prestressed shot peening technological
advances into the process of additi~e manufacturing, resulting in an innovative
post-processing technology that effectively resolves the defects in additivemanufactured
components (II 0) and enhances material performance, thereby
facilitating the development of high-quality, efficient products for specific
applications.
2. The apparatus as specified in claim l, wherein the automated controlled unit (I 04), wire
feeder (105), manufacturing chamber is intended for manufacturing a three-dimensional
metallic component (108).
3. According to the methods outlined in claims I and 2, the apparatus for post-processing an
additively manufactured metal component (108) comprises: shot peening equipment,
which includes a treatment chambers (113), a nozzle (Ill), shot media, nozzle wheels,
and control systems ( 112), designed to precisely post-process an additively manufactured
metal part (106) positioned in the treatment chamber (113), utilising the optimised
parameters pertinent to shot peening the part:
4. The apparatus outlined in claims l, 2, and 3 features an innovative post-processing
technology tailored by four-point bending, comprising main frames (117), rollers (116), a
test specimen holder (115), and control systems (II2), is configured to induce a
prestressed condition in an additively manufactured metal component (I 10), alongside
shot peening executed as specified in claim 3 .
5. The method of claims 2, 3, and 4 entails evaluating the attributes of post-processing
technologies and selecting a post-processing technology from a variety of circumsta~_ _. .,E.4.,..S~Ifi ·
predominantly based on the advantageous qualities of one or more ~these technol"" . &n '
6. The system described in claim 4 utilises a newly developed novel prestress d sh~ f e
peening post-processing technology that diminishes segregation and inhib "'" ~ 'J
formation of secondary phases, thereby improving surface and mechanical prop • mo'lCS
while minimising residual stresses and cracking in the addti ~"- .-:<~fufac_!l!Ie
superalloy.

Documents