At 2:23 on December 8, China successfully launched the Chang'e-4 probe with the Long March IIIB launch vehicle at the Xichang Satellite Launch Center, and began the first human soft-landing probe on the back of the moon. In this aerospace mission, the Shanghai Institute of Ceramics, Chinese Academy of Sciences has undertaken thermal control coatings, high-temperature oxidation-resistant coatings for refractory alloys, high-friction anti-cold-weld coatings, high-temperature insulation screens, and flexible thin-film thermal-control coatings. And the development of key materials such as low-temperature multilayer insulation components.
Thermal control coatings: Developed the patrol moving mechanism, motor mechanism, mechanical arm mechanism, panoramic camera mechanism titanium alloy, magnesium alloy micro-arc oxidation thermal control coating, stainless steel gray chemical conversion heat for lander engine heat shield and protective tube Control coating, stainless steel high absorption chemical conversion thermal control coating, lander moon and night temperature collector low radiation gold thermal control coating, lander ramp and guardrail mechanism aluminum alloy bright anodized thermal control coating, laser lattice device, There are more than ten kinds of inorganic thermal control coatings, such as payload black anodized thermal control coatings for lithium ion batteries, flexible thin film thermal control coatings on the surface of inspectors, and coating-type low-ratio thermal control coatings. Some of these coatings are specially made by Chang'e and are used on spacecraft for the first time. They have the characteristics of good temperature control performance, strong space environment radiation resistance, and excellent coating uniformity, which ensure that the components and motors in these mechanisms are normal. The working temperature level has played an important role in the safe landing of the lander, the patrol survey on the moon, and the normal operation of the robotic arm.
Refractory alloy high-temperature anti-oxidation coating: As the moon is 380,000 kilometers away from the earth, the flight distance of Chang'e satellite is greatly increased compared to the average satellite flight distance, and it needs to go through multiple orbital changes to achieve the "falling moon", and the attitude control engine life requirements are greatly extended It has put forward more demanding requirements for its refractory alloy high-temperature anti-oxidation coating. It must withstand higher temperatures, greater scouring speed, and a more severe oxygen-rich environment, which makes it extremely difficult to develop. The refractory alloy high-temperature anti-oxidation coating developed by Shanghai Silicate successfully passed the assessment of the long-life ground bench test and was successfully applied to Chang'e-1 to Chang'e-4, and will continue to provide technical support for subsequent mission models .
High-friction anti-cold welding coating: applied to the contact point of solar cell array, not only to ensure that the solar array of the patrol can achieve reliable and effective solar cell array during acceleration and deceleration, such as launching, flying to the moon, landing, and separation of the two devices. Closed, to avoid accidental dissipation and collision, to ensure the integrity of the solar cell array; its cold-welding function ensures the elimination of conditions such as vacuum cold welding caused by the solar cell array undergoing long-term compaction and collapse, which guarantees the solar panel Smooth development. At the same time, the fulcrum of the high-friction anti-cold-welding coating has also played an important role in the frequent opening and closing and reliable contact of solar cell arrays.
High-temperature heat shield: A key component of a variable thrust engine necessary to achieve a soft landing on the lunar surface of the lander. Due to the high temperature of the combustion chamber and the nozzle during the operation of the engine, the high-temperature insulation screen developed by Shanghai Silicate surrounded the high-temperature environment like a "skirt", forming a path between the engine and the surrounding electronic components. The barrier effectively reduces the effect of engine operation on the temperature of the detector body.
Flexible thin film thermal control coating and low-temperature multilayer thermal insulation components: Chang'e-4 is affected by the day and night temperature changes on the surface of the moon. The lowest temperature can reach minus 200 ° C and the highest can exceed 100 ° C. The operating temperature of a single machine such as a probe is generally about -40 ~ + 50 ° C. Once it exceeds the normal temperature range, it may cause the function of the single machine to fail, and even cause damage to the single machine. The low-absorption ratio flexible thin film secondary surface mirror developed by Shanghai Silicate provides temperature control guarantee for the normal operation of the inspector. The low-temperature multilayer thermal insulation component can ensure that the temperature of the single machine is kept within the normal operating temperature range, and can be separated in two directions. Heat, prevents external heat from being transmitted to the inside when the external temperature is high, and prevents internal heat from leaking to the outside when the external temperature is cold.
According to Xinhua News Agency, the Chang'e-4 probe will experience earth-moon transfer, near-month braking, and moon-circle flight, and eventually achieve the first soft landing of the back of the moon. The orbiting "Bridge Bridge" relay star realizes relay communication between the back of the moon and the earth.
At 2.23 on December 8, China successfully launched the Chang'e 4 probe at the Xichang Satellite Launch Center with the Long March 3B launch vehicle, and started a new journey of lunar exploration.