It is understood that due to the extremely harsh and complicated service conditions on the surface of Mars, the rover puts forward extremely high requirements for materials. Firstly, the lightweight index is extremely high, and the weight is calculated in grams; Secondly, the material must be wear-resistant to meet the requirements of long-distance ground driving; The material should be high strength and isotropic to meet the load demand; At the same time, it must have high plasticity to avoid failure due to sudden situations such as violent collision and puncture. Because of these requirements, traditional metal materials are difficult to meet, so it is necessary to develop new composite materials with high performance.
The Institute of Metals, Chinese Academy of Sciences received this task to carry out research and development on 20 15. Researcher Ma said that because this is the first development task of the rover in China, coupled with foreign technology blockade, there is almost no experience in the selection of new materials for this rover. In the case of tight time and heavy tasks, researchers achieved technical breakthroughs such as material composition design, large-size ingot preparation and controllable plastic deformation processing in only three months, and developed a new type of aluminum-based silicon carbide composite with high strength and toughness. Among them, how to balance the strength, wear resistance and plastic toughness of composites by adjusting the amount of silicon carbide and optimizing the composition of matrix alloy is the key to meet the engineering requirements. After continuous improvement and research and development, the wear resistance of the final material is dozens of times that of aluminum alloy, but the weight of the processed parts is lighter than that of aluminum alloy. This result has given the designers and manufacturers of the rover great confidence. With this performance, the new material successfully passed the strict examination in the stage of environmental simulation experiment, and the related technical scheme was highly recognized. Finally, it is applied to the "skeleton structure" of dozens of components such as the structure, mechanism and instrument of the rover, making the rover the spacecraft with the largest proportion of aluminum-based composite materials in China.
Behind the successful development of new materials is China's unremitting exploration of localization of metal matrix composites. It is reported that the research and development of metal matrix composites in China started late, and it is faced with worldwide problems such as uncontrollable microstructure and properties, difficult preparation and processing, and has long been in the predicament of slow technological progress and insufficient demand traction. The research team of Institute of Metals, Chinese Academy of Sciences is one of the earliest teams in China to carry out research on metal matrix composites. In recent years, the team has broken through a number of key technical bottlenecks, prepared large-size ingots, and improved the plastic forming ability of materials. After long-term accumulation, the achievements of metal matrix composites have been authorized by more than 30 national invention patents and successfully applied in batches. At present, Institute of Metals of Chinese Academy of Sciences has developed into an important R&D and industrialization base in the field of metal matrix composites in China, with an annual output of nearly 100 tons.
The application of new materials in the Mars rover is an important event in the field of material research and development in China. Researchers from the Institute of Metals of the Chinese Academy of Sciences said that in the future, there will still be a great demand for metal-based composites in China's deep space exploration, large aircraft, general aviation, nuclear power autonomy, rail transit and other fields, and the Institute of Metals of the Chinese Academy of Sciences will also carry out research to try to overcome the * * * problems faced by the international community such as high-strength and toughness design of composite materials, simulation of organizational performance, and fine control of interface structure.