Replace large domestic aircraft with titanium alloy
In 2006, the State Council approved the establishment of a large aircraft scheme demonstration Committee. Cao Chunxiao is the only member engaged in aviation material research. After the launch of the project, Cao Chunxiao served as a member of the expert advisory committee and traveled all over the country. The large aircraft project covers civil and military aircraft, and the civil aircraft code is C919.
The less weight an airplane has, the better. The weight of the airplane itself is a percentage of its total take-off weight, which is called the "structural weight coefficient of the airplane". In the past 70 years, no aircraft has had a structural weight factor of less than 27%, which is due to the performance of large components and the manufacturing capacity of large components. Titanium material becomes the key. Titanium alloy materials and forging technology can reduce the structural weight of aircraft and improve its competitiveness.
Today, the more economically demanding C919 uses 8% titanium, comparable to 7.5% of the Boeing 777 in the U.S. Large aircraft can not be manufactured without large forgings which require high technology. In the column "Academician's Introduction", Cao Chunxiao shows titanium forging joint for C919, named TC4, weighing 600 kg. To make similar forgings, China has built the world's largest 80,000-ton hydraulic press.
In November 2015, C919 with China's independent intellectual property rights was officially unveiled worldwide in Shanghai. Cao Chunxiao was thrilled at the scene and his dream of more than forty years came true at last.
On May 5, 2017, the C919 airliner made its first successful flight in Shanghai. In March 2021, C919 took the first order. By early 2022, the C919 had taken 815 orders.
