Combination application of Titanium Alloy and 3D printing

A 3D printing technology called "Laser Additive Manufacturing" uses laser to melt metal powder and can "print" products of almost any shape. Its biggest feature is that the material used is metal, and the "printed" products have extremely high mechanical properties and can meet the needs of different industries such as aerospace, molds, automobiles, medicine, dentistry, and handicrafts.

3D printing technology can be traced back to 1984. Charles Hull first developed the technology to print 3D objects from digital data and developed the first commercial 3D printing machine 2 years later. Subsequently, its basic technology and specifications were continuously improved throughout the 1990s, and it was put into use in the 21st century.

Titanium is a material with only half the density of steel but far stronger than most alloys. It is widely used in the aerospace industry. The United States is the first country to develop titanium alloy 3D printing technology. In 1985, the United States secretly began research on titanium alloy laser forming technology under the leadership of the Department of Defense, and made it public in 1992. Subsequently, the United States continued to develop this technology, and in 2002, it installed laser-formed titanium alloy parts on fighter aircraft for testing.

However, because the technical problems of titanium alloy deformation and fracture during the manufacturing process cannot be solved, the United States has never been able to produce high-strength, large-size laser-formed titanium alloy components. In 2005, Aeromet, a commercial company engaged in titanium alloy laser forming and manufacturing business in the United States, went bankrupt because it was unable to produce large-scale complex titanium alloy components whose performance met the main bearing capacity requirements and failed to realize valuable market applications. Other national laboratories in the United States are also unable to overcome this problem. Currently, they can only print small-sized titanium alloy parts and repair the surface of titanium alloy parts.

China's titanium alloy 3D printing comes from behind

China's titanium alloy laser forming technology started late, and it was not until 1995 that the United States declassified its R&D plan and began research three years later. In the early days, I basically followed the study in the United States and set up laboratories to conduct research in many universities and research institutes across the country. Among them, the AVIC Laser technical team has made the most significant achievements.

As early as around 2000, the AVIC Laser Technology Team had begun to invest in the research and development of "3D laser welding rapid prototyping technology". With the continued support of the Chinese government, especially the military funds, after several years of research and development, it solved the problem of "inert gas protection system" , "thermal stress dispersion", "defect control", "lattice growth control" and many other world-wide technical problems, to produce products with complex structures, sizes reaching the order of 4m, and performance that meet the requirements of main load-bearing structures, and have commercial applications value.

At present, China has the technology and ability to use laser to form complex titanium alloy components exceeding 12 square meters, and has invested in the prototypes and product manufacturing of multiple domestic aviation scientific research projects. It has become the only major master in the world that masters laser forming of titanium alloys. A country where load-bearing components are manufactured and applied in installation engineering.

After solving the problems of material deformation and defect control, titanium alloy structural components produced in China quickly became a unique advantage of China's aviation research and development. Due to its light weight and high strength, titanium alloy components have broad application prospects in the aviation field. At present, the proportion of titanium alloy components on advanced fighter aircraft has exceeded 20%.

Traditional titanium alloy parts manufacturing mainly relies on casting and forging. Cast parts are easy to manufacture in large sizes, but they are heavy and cannot be machined into fine shapes. Although forging cutting has better precision, the main load-bearing component of the American F-22 fighter is the large cast titanium alloy frame. However, there is serious waste in parts manufacturing, 95% of the raw materials will be cut off as scrap, and the size of forged titanium alloys is strictly limited: a 30,000-ton large hydraulic press can only forge parts no more than 0.8 square meters, even the world's largest 8 For a 10,000-ton hydraulic press, the size of the forged parts cannot exceed 4.5 square meters. Moreover, neither technology can manufacture complex titanium alloy components, and welding will encounter terrible titanium alloy corrosion.

Laser titanium alloy forming technology completely solves this series of problems. Due to the use of superposition technology, it saves 90% of very expensive raw materials. In addition, there is no need to manufacture special molds. The processing cost that was originally equivalent to 1 to 2 times the material cost is now Only 10% of the original is needed. It is roughly estimated that the cost of processing a titanium alloy complex structural part weighing 1 ton is about 25 million yuan, while the cost of laser 3D welding rapid prototyping technology is only about 1.3 million yuan, and its cost is only 5% of the traditional process.

More importantly, many complex structures of titanium alloy structures can be integrated into one piece through 3D printing, which not only saves man-hours, but also greatly improves the strength of the material. If the F-22's titanium alloy forgings are manufactured using China's 3D printing technology, the weight can be reduced by up to 40% while maintaining the same strength.