Application of Titanium Alloy in Laser/Electron Beam Additive Manufacturing

--- Reprinted Self-moving Technology
The rapid development of additive manufacturing technology provides a new method for the production of titanium alloy, and the laser/electron beam additive manufacturing method has been widely studied by domestic scholars in the production of titanium alloy.
Titanium and titanium alloys have broad application prospects in various industrial fields, including shipbuilding, aerospace, automobile manufacturing, etc., due to their excellent physical and chemical properties such as low density, high temperature resistance, and corrosion resistance. At the same time, it is also one of the important materials in the national defense industry. The application of titanium alloy has played a huge role in promoting industrial development, and its product quality has been greatly improved because of its superior performance to traditional materials, which meets the requirements of industrial development for new materials and new processes, and accelerates the development of modern industry. With the continuous improvement of titanium productivity, titanium alloy has become the third metal in industrial production.
Additive manufacturing (Additive Manufacturing,AM), also known as "3D printing", is a digital manufacturing technology that can realize dieless forming of components. It has the characteristics of integrated design and manufacturing, high processing accuracy, short cycle, excellent physical and chemical properties of products, etc. Additive manufacturing technology has developed rapidly since the 1970 s. Because of its huge differences with traditional manufacturing technology, it has become a research hotspot in the industrial field, and has developed rapidly in many fields of modern industry.
The rapid development of additive manufacturing technology can theoretically realize any single or multi-metal composite structure, which provides a new method for the manufacture of complex structural parts.
Laser beam and electron beam as a high-density beam source, high energy density and can be controlled, known as the most advanced manufacturing technology in the 21st century. At present, laser/electron beam additive manufacturing is mainly divided into laser metal deposition (LMD) Deposition, laser selective melting (Selective Laser Melting,SLM) technology, electron beam fuse deposition (Electron Beam Free Form Fabrication,EBF3) technology, and electron beam selective melting (Electron Beam Melting,EBM) technology, which have been widely studied in the field of titanium alloy additive manufacturing.

Laser Metal Deposition (LMD)

LMD technology is a welding process that introduces material into a molten pool generated by a high-power laser for welding molding. LMD belongs to the scope of the directed energy deposition process. The filler material usually introduced is powder, which is injected through a tapered ring nozzle surrounding the laser beam. The added material forms a weld, and then the underlying metal is coated. The process is used in cladding applications where the wear resistance of the component is increased, in repair applications where material is added to a worn component, or in free-form fabrication of geometries, where LMD results in a smaller heat affected zone, low dilution, and low residual stress in the component compared to other types of welding.

For titanium alloy LMD technology additive manufacturing is relatively stable, the mechanical properties of the additive parts basically meet the minimum standard of forgings, for some specific requirements of titanium alloy to be added to the heat treatment after manufacturing to meet the requirements of use.

Selective Laser Melting (SLM)

SLM technology is an additive manufacturing method that uses a high-energy laser beam to melt the metal alloy powder on the two-dimensional section after slicing the three-dimensional model, and prints the solid parts layer by layer from bottom to top. SLM technology uses path planning software to scan the contour data, and imports the data after path planning into SLM equipment. The industrial control computer controls the selected laser beam to melt the metal alloy powder layer by layer according to the scanning path of each layer contour, layer by layer stacked into a dense three-dimensional metal part solid.

Additive manufacturing of Ti6Al4V SLM technology is relatively easy to realize. Further research is needed for additive manufacturing of titanium and other element alloys. Preheating or other heat treatment methods and oxygen content control methods are needed to enhance the mechanical properties of additive manufacturing of other titanium alloys and obtain high-quality research samples.

Electron Beam Fuse Deposition (EBF3)

Electron beam fuse technology is a process that uses electron beam as a heat source and uses off-axis wire to build parts, and the near-net-shaped parts manufactured by this additive manufacturing process need to be subsequently finished by the material reduction process. The principle is that in a vacuum environment, a high-energy density electron beam bombards the metal surface to form a molten pool, the metal wire is fed into the molten pool through a wire feeding device and melted, and the molten pool moves according to a pre-planned path, and the metal material solidifies and accumulates layer by layer to form a dense metallurgical combination until a metal part or blank is manufactured. There are relatively few studies on electron beam fuse deposition additive manufacturing of titanium alloys, mainly in the field of deformation control with the help of finite element analysis software. The analysis shows that the electron beam fuse deposition additive manufacturing can overcome the disadvantages of the traditional titanium alloy processing method, and provide the basic theoretical guidance in the practical application process with the help of finite element analysis software.

Electron Beam Selective Melting (EBM)

Electron beam selective melting technology is through electron beam scanning, melting powder materials, layer by layer deposition to manufacture 3D metal parts, due to the high electron beam power, the material of the electron beam energy absorption rate is high, EBSM technology has high efficiency. Small thermal stress and other characteristics, suitable for titanium alloy, titanium aluminum alloy and other high-performance metal materials forming manufacturing.

EBM research on Ti6Al4V is relatively extensive, and it is found that EBM technology additive manufacturing for Ti-Nb alloys is still difficult to solve the diffusion problem of Nb particles, which will lead to uneven microstructure, so more process optimization tests are needed for the additive manufacturing of Ti-xNb alloys to improve material performance.

END

With the rapid development of modern industry, lightweight design has become the development direction of structural parts, and the performance and quality requirements of structural parts have become more and more stringent. The rapid development of titanium alloy additive manufacturing technology can further expand the application range of titanium alloy structural parts, improve the performance of titanium alloy additive parts, and enhance structural stability. The additive manufacturing technology of titanium alloy solves the processing problem of precision structural parts and further increases the application range of titanium alloy. With the rapid development of additive manufacturing, titanium alloy additive manufacturing technology is changing with each passing day. Experts and scholars at home and abroad optimize the process, stabilize the additive manufacturing process, reduce or avoid the defects of additive manufacturing structure, and make the titanium alloy additive manufacturing technology continue to develop in the direction of green, efficient and stable.
For the rapid development direction, the current stage of laser/electron beam additive manufacturing process is relatively mature, should continue to explore the economic applicability of laser additive manufacturing, from the actual production of assembly accuracy to the production and manufacturing process optimization process, and then reduce the production cost, for titanium alloy additive manufacturing structure large area production application to lay the foundation.