For high-speed production of high-quality titanium parts,
Development of metal 3D printing technology using arc and wire
Produce large parts 5 times faster than with powder materials


The Korea Institute of Industrial Technology announced on the 8th that it had developed a metal 3D printing technology using electric sparks, Arc and Wire, and achieved optimization of the titanium material process.

Titanium is as strong as steel, but weighs only half as much, and has the characteristics of not rusting and withstanding heat well, so it is attracting attention as a next-generation component material for the aerospace, energy, plant, and defense industries. However, it is hard enough to be considered a typical difficult-to-cut material, making it difficult to process, and it is difficult to weld because it oxidizes at high temperatures.

Alternatively, there is a processing method using metal 3D printing, but the powder material and heat source are expensive, and productivity is low because only about 900g can be laminated per hour. Dr. Gam Dong-hyeok's research team in the Biomimetic Bonding and Lamination Research Division has developed a metal 3D printing technology that uses an arc as a heat source instead of the existing laser and replaces the powder material with a wire.

The arc heat source used in this technology has the advantage of being very inexpensive to build and is advantageous for manufacturing large parts, as it costs only 1/10th of the price of laser equipment. In addition, because wires are melted and laminated instead of powder, the material price is about 80% cheaper, material waste is reduced by 65%, and the lamination speed is improved by about 5 times.

However, this technology uses a direct current as a power source when laminating general metal materials and utilizes a method of laminating materials at a different angle from the heat source, but titanium had difficulty with the deterioration of lamination quality and system automation. This is because titanium has a unique characteristic of emitting hot electrons, so when direct current is used to melt the wire, an unstable plasma is generated.

In this case, heat is not properly transferred, so the material splashes around or accumulates unevenly, creating bubbles that lead to defects. The research team independently developed a short-circuit transition technology based on AC power that periodically changes size and direction over time and a helium gas environment creation process to solve the titanium component processing problem.

By utilizing the short-circuit transition technology based on the AC power supply, the voltage can be lowered and the current can be reduced by changing the polarity of the arc. At this time, if the heat source and the wire are placed on the same axis and the material is melted, it is possible to stack it cleanly and evenly without splattering. In addition, a processing method that prevents titanium oxidation by creating a helium gas environment has been developed.

The research team is also developing a composite system that integrates lamination, post-processing, and diagnosis to overcome the shortcomings of the arc wire lamination method, which makes it difficult to precisely manufacture products with complex shapes. It is expected that real-time control of process variables such as temperature and shape will be possible with the inclusion of layered monitoring and AI quality prediction technology, and that even complex shapes can be produced with high quality.

Dr. Gam Dong-hyeok said, “This technology will realize high-speed, high-quality, and large-area metal 3D printing systems,” and added, “We plan to start with lightweight defense parts with high titanium demand, and expand the field to energy and chemical plants, and even the aerospace industry in the future.”