China achieves mass production of rocket propellant tank domes using cryogenic forming technology

A Chinese research team has successfully mass-produced rocket propellant tank domes using their pioneering cryogenic forming technology, which can reduce production cycle time by more than 90 percent.

The team, from the lab of high-performance precision manufacturing at Dalian University of Technology's School of Mechanical Engineering, has developed the world's first large cryogenic forming press to make one-piece rocket propellant tank domes over two meters in diameter from aluminum alloys.

In cooperation with a Chinese company, they have realized the production capacity of about 1,000 tank domes per year.

"The key to cryogenic forming is cooling large plates into the cryogenic zone. This equipment has broken through the challenges of rapid transport and precise temperature control of large-volume liquid nitrogen, as well as coordinated loading control of multiple parameters, including temperature, pressure, and displacement. It enables the control of liquid nitrogen at minus 190 degrees Celsius, the designed cooling of materials, and thus stable manufacturing of large components. It can reduce the production cycle time by 90 percent from more than one week to just a few hours," said Fan Xiaobo, a researcher at the school.

The cryogenic forming press can make a rocket propellant tank dome out of a four-millimeter aluminum alloy plate in a single step, with a thickness deviation of less than 0.3 millimeters.

The core enabler of the stable operation of this equipment is the aluminum alloy cryogenic forming technology pioneered by the team.

"Generally, metals become brittle at cryogenic temperatures, so they are considered harmful. However, our research team discovered that aluminum alloys in a specific state not only avoid cold brittleness but also exhibit higher elongation and hardening indexes at cryogenic temperatures. Using this abnormal phenomenon, we have developed the world's first aluminum alloy cryogenic forming technology, and transformed the conventional approach of 'heating when ambient temperature fails' to a cryogenic approach, enabling us to make a monolithic tank dome from a thin plate in one go. The forming press can generate a finished product that can be used directly, requiring no further welding or milling," Fan said.

The new tank domes have been successfully applied in flight missions of Long March-12 and Long March-7A Y14 carrier rockets.

"This technology enables the production of one-piece tank domes, which is especially critical for reusable rockets. We will continue to push forward and apply this cryogenic forming technology to enable self-reliance in aircraft and unmanned systems and to promote low-cost manufacturing of thin-walled structures for new-energy vehicles and high-speed trains," said Qi Chang, head of the school.

China achieves mass production of rocket propellant tank domes using cryogenic forming technology

China achieves mass production of rocket propellant tank domes using cryogenic forming technology

Japan's reliance on U.S. economic policy is allowing foreign funds to acquire Japanese assets at bargain prices, according to Japanese economist Kazuhide Uekusa.

He warned that the government's economic and defense strategies prioritize foreign capital and political profits over public welfare, failing to bring true prosperity to ordinary citizens.

The Bank of Japan (BOJ) on Friday raised its policy interest rate by 0.25 percentage points to 1.25 percent, the highest in about 31 years, following a two-day board meeting.

According to Uekusa, the timing of the shift aligns perfectly with the interests of large American funds.

"The Takaichi Cabinet has been reluctant to raise interest rates, thus allowing the yen to continue to depreciate. I think this is actually equivalent to helping foreign capital purchase Japanese assets at a low price. However, U.S. Treasury Secretary Scott Bessent has recently made a clear adjustment to the policy direction of the U.S. dollar against the Japanese yen, promoting the appreciation of the Japanese yen. The reason is that some large funds in the United States have basically completed their investment layout in Japanese assets," said Uekusa.

Uekusa also said Japan cannot attempt to revitalize its economy by expanding military spending and supporting the defense industry, and such a military buildup strategy is unlikely to bring about true prosperity and stability.

"I think it is true that the Japanese economy has been stagnant for a long time. However, to expand military spending in an attempt to revitalize the economy is, in my opinion, an extremely foolish and even crazy move. To achieve peace and stability in Japan, the foundation should be to establish friendly relations with neighboring countries rather than military expansion. The reason why the Japanese government attaches so much importance to the military industry is that it can generate huge profits, and a part of these profits may flow back to political parties or political figures through various means. I don't think this is at all for the benefit of the people," he said.

Japanese economist criticizes gov't policies for enabling cheap asset sales to foreign funds