At 11:30 on October 19, 2021, China’s self-developed monolithic solid rocket engine with the world’s largest thrust, highest impulse-to-mass ratio, and engineerable application was successfully tested in Xi’an, marking that China’s solid-carrying capacity has been achieved substantially. Upgrading is of great significance to promoting the development of large and heavy launch vehicle technologies in the future.
The successful development of solid rocket motors not only embodies the hard work and wisdom of countless scientists, but also cannot do without the contributions of many chemical materials such as tungsten and molybdenum products.
A solid rocket motor is a chemical rocket motor that uses solid propellant. It is mainly composed of a shell, a grain, a combustion chamber, a nozzle assembly, and an ignition device. When the propellant is burned, the combustion chamber must withstand a high temperature of about 3200 degrees and a high pressure of about 2×10^7bar. Considering that it is one of the components of the spacecraft, it is necessary to use lighter high-strength high-temperature alloy materials such as Made of molybdenum-based alloy or titanium-based alloy.
Molybdenum-based alloy is a non-ferrous alloy formed by adding other elements such as titanium, zirconium, hafnium, tungsten and rare earths with molybdenum as the matrix. It has excellent high temperature resistance, high pressure resistance and corrosion resistance, and is easier to process than tungsten. The weight is smaller, so it is more suitable for use in the combustion chamber. However, the high temperature resistance and other properties of molybdenum-based alloys are usually not as good as tungsten-based alloys. Therefore, some parts of the rocket engine, such as throat liners and ignition tubes, still need to be produced with tungsten-based alloy materials.
Throat lining is the lining material for the throat of the solid rocket motor nozzle. Due to the harsh working environment, it should also have similar properties to the fuel chamber material and the ignition tube material. It is generally made of tungsten copper composite material. Tungsten copper material is a spontaneous sweat cooling type metal material, which can effectively avoid volume deformation and performance changes at high temperatures. The principle of sweat cooling is that the copper in the alloy will be liquefied and evaporated at high temperature, which will then absorb a lot of heat and reduce the surface temperature of the material.
The ignition tube is one of the important parts of the engine ignition device. It is generally installed in the muzzle of the flamethrower, but needs to go deep into the combustion chamber. Therefore, its constituent materials are required to have excellent high temperature resistance and ablation resistance. Tungsten-based alloys have excellent properties such as high melting point, high strength, impact resistance, and low volume expansion coefficient, making them one of the preferred materials for the manufacture of ignition tubes.
It can be seen that tungsten and molybdenum industry has contributed to the success of the solid rocket engine test run! According to Chinatungsten Online, the engine for this test run was developed by the Fourth Research Institute of China Aerospace Science and Technology Corporation. It has a diameter of 3.5 meters and a thrust of 500 tons. With a number of advanced technologies such as nozzles, the overall performance of the engine has reached the world’s leading level.
It is worth mentioning that this year China has carried out two manned spacecraft launches. That is, at 9:22 on June 17, 2021, the Long March 2F carrier rocket carrying the Shenzhou 12 manned spacecraft was launched. Nie Haisheng, Liu Boming, and Liu Boming were successfully launched. Tang Hongbo sent three astronauts into space; at 0:23 on October 16, 2021, the Long March 2 F Yao 13 carrier rocket carrying the Shenzhou 13 manned spacecraft was launched and successfully carried Zhai Zhigang, Wang Yaping, and Ye Guangfu into space. Sent into space.