Li Qingyun's technological achievements.

/kloc-in the autumn of 0/958, Li Qingyun returned to China and was assigned to Beijing Institute of Nonferrous Metals for scientific research. In his prime, he devoted himself to the research of rare metal processing as young as China with the enthusiasm of serving the motherland.

During the period of 1960- 1963, Li Qingyun presided over the research on the small-batch production of rare metals such as titanium, zirconium, tantalum, niobium and rhenium, produced plates, rods, wires and powders of these metals in small batches, developed niobium-tantalum seamless tubes and tantalum tube heaters, studied the recrystallization texture of niobium for the first time in China, and solved the problem of deep drawing ears of niobium materials. He also developed a thin-walled sintered tungsten tube with a diameter of 30 mm and a length of 300 mm, which was used as a heater in a high-temperature furnace. From 1964 to 1965, Li Qingyun began to study superconducting materials when he was the deputy director of the processing laboratory. At that time, the research of superconducting materials in China was always limited to niobium zirconium alloy, but the superconducting critical magnetic field of this alloy was low and its processability was poor, which led to the research hovering at a low level for a long time and failed to make a breakthrough. Li Qingyun took the lead in proposing and carrying out research on Nb-Ti superconducting alloys in China, successfully prepared superconducting wires with excellent properties, and turned its research focus to Nb-Ti superconducting materials. Because he opened up a brand-new way to study superconducting materials, his technical achievements were among the best in China. In the third-line construction started in the mid-1960s, the state specially approved the establishment of the first superconducting materials laboratory in Baoji.

During this period, he also organized and undertook the development of zirconium -2 alloy tube, the key material of the national "09" project. He led the research team, explored the control method of alloy composition and the conditions for rolling pipes, and obtained a series of research results, which not only accumulated experience for the production of zirconium -2 alloy pipes in Beijing Institute of Nonferrous Metals, but also laid a good foundation for the production of zirconium pipes in Baoji Nonferrous Metals Processing Factory, a research base for rare metal materials production in China. The development of Zr -2 alloy tube has contributed to China's "09" project, and won the 1978 National Science Conference Award and the 1988 National Science and Technology Progress Special Prize (sub-item Award). In these two heavy awards, Li Qingyun's painstaking efforts and sweat are condensed. In addition, he also organized the development of powder metallurgy tungsten plate and rocket nozzle electron bombardment furnace.

In the early 1960s, China's rare metal processing industry initially achieved industrial production, but the scale was not large. In order to meet the growing demand of national defense industry and cutting-edge science and technology for rare metal materials, the former Ministry of Metallurgy held a meeting on the construction of the northwest third line in Lanzhou in February 1964, and decided to establish a research base for rare metal production in Baoji, Shaanxi Province, and transferred a large number of technicians, cadres and workers from Beijing Nonferrous Metals Research Institute and Shenyang Nonferrous Metals Processing Factory to participate in the construction of the 902 plant.

1In August, 965, Li Qingyun gave up Beijing's superior living environment and went to the hinterland of the northern foot of Qinling Mountains with great ambition to develop the rare metal industry in China, and invested in the preparation and start-up of the 902 factory. In the preparation process, as the deputy chief of the research department, he presided over the establishment of the information, physics, chemistry, titanium alloy, powder metallurgy and alloy processing research room of the institute (now Northwest Institute of Nonferrous Metals). During his tenure as the director of the alloy processing room, he organized scientific and technical personnel to conduct a series of research on metal materials. When many technical problems were encountered in rolling seamless slender molybdenum tubes, Li Qingyun proposed to use hydrogen and oxygen as heating sources instead of acetylene gun, which not only avoided pollution, but also made the rolling process stable, which not only rolled long seamless molybdenum tubes for the first time in China, but also provided a basis for designing and manufacturing heat pipe machines in China. After that, the mechanical department designed and manufactured the first batch of series heat pipe machines in China, which provided the necessary equipment conditions for industrial production. This heating method has also been successfully applied to the spinning of various tungsten-molybdenum tubes.

In the early 1970s, Li Qingyun began to research and improve titanium production technology. At that time, the pure titanium pipe was corroded when it was used as a condenser in chlor-alkali industry, which led to doubts about whether titanium could be used, which had a negative impact on the popularization and application of titanium. Through research, he replaced the cold expansion method with argon arc welding technology, which solved the problem of crevice corrosion. This technology has been used in China until now. During the period of 1978, when Li Qingyun was the director of the Science and Technology Office of the factory, he organized technicians to tackle key problems of titanium alloy materials for Spey engines, and overcame many difficulties, so that the materials reached the level of similar products in Britain in terms of microstructure, mechanical properties and processing flow, and the quality met the requirements, and won the Science and Technology Progress Award of China Nonferrous Metals Industry Corporation. He also organized the research on electrolytic descaling of titanium and titanium alloy forging billets, put forward and organized the production process test of direct extrusion of pure titanium ingots, which reduced the geometric loss during casting, increased the yield of pure titanium pipes by more than 10%, greatly shortened the process flow, and opened up a new way for the production of pure titanium pipes.

From 1978 to 1984, Li Qingyun successively served as the deputy factory (institute) director and chief engineer. He led technicians to study and solve the process and quality problems of exported titanium alloy products. In China, plasma argon arc welding is used for the first time to replace the traditional argon arc welding method, which eliminates the tungsten inclusions in the ingot, and studies and controls the segregation of titanium alloy ingot, so that the delivery task of 265 tons TC4 titanium alloy ingot ordered by American businessmen can be successfully completed. The quality of titanium ingot meets the standard requirements after inspection by the US. In the same year, TC4 titanium alloy ingot won the national gold medal. "Baoji Titanium" has gained a firm foothold in the international market and gained a good reputation.

The surface treatment of titanium processing materials in the production process needs a lot of acid and produces a lot of waste acid. Li Qingyun decided and organized the recovery experiment of titanium pickling waste liquid, and designed and manufactured its own special recovery device. The compound precipitation method is adopted to recover the waste liquid, which realizes the closed circulation of pickling solution, reduces the discharge of 1000 tons every year, not only eliminates environmental pollution, but also saves the cost of 500,000 yuan every year.

In order to reduce the foreign exchange expenditure of the factory, Li Qingyun organized technicians to carry out trial-production research on large copper crucible for vacuum electric arc furnace, and developed a large copper crucible with a maximum diameter of 700 mm by argon arc welding and arc welding, ending the long-term dependence on imports; He also successfully developed a vacuum plasma welding box and studied the welding process, which was applied to material welding; 120 kW electron bombardment furnace and titanium epoxy coating were successfully developed. The coating shows high adhesion and corrosion resistance, and is used in many industries.