Damage Characteristics Of Micro Particles High Speed Impaction On The Spacecraft Optical Components

Along with growing degeneration of space debris environment,low-Earth orbit was covered with huge amounts of micron and nanon sized space debris.Although the single impact will not cause effect on spacecraft,the cumulative impact can lead to the functional components of spacecraft,such as solar panel,optical lens,thermal control coatings,etc.damage.Early in the 1970 s,the research on space debris space-based detection and ground simulation experiments were carrid out.Micro and nano particles will spurt out while the spacecraft were impacted by millimetre or even larger space debris,and micro particles also could formed by solid engine combustion products.Micro particles impact optical components of spacecraft not only form impact craters,but also could form adsorption layer under certain conditions to reduce the performance of optical components.In addition,from the perspective of space strategic defense,the accelerator with single micro particle emissive capability and related research of damage characteristics already cannot meet the demand,the equipment that could meet the demand of emitting micro particles swarm and it is related research of damage characteristics need to be solved urgently.In light of the above reasons and background,in order to study the damage characteristics of spacecraft optical components formed by micro particles impact,the launch system of micro particles swarm based on the two-stage light gas gun was established in this paper,and optical components of the spacecraft are simulated by glass target,and then experiments that some kinds of typical materials of micro particles swarm impact glass target were carried out,and the damage characteristics of impact crater and adsorption layer on glass target were discussed.The formation mechanism of adsorption layer morphology was studied on the basis of the damage pattern and process of single particle impact the glass target,distribution characteristics and of adsorption layer of particles impact the glass target,and the movement pattern of micro particles.A micro particles swarm launch method based on two-stage light-gas gun is proposed which based on the existing two-stage light-gas gun system used for launching micron particle.In order to meet technical requirements for particles launch and velocity measurement,some related components has been improved or designed which based on the existing two-stage light-gas gun system used for launching micron particle.Related work includes improving the design of sabot and segregation apparatus,designing velocity measuring device with structure of three-layer insulated wire mesh which based on the on-off principle,designing high speed airflow block device to reduce impact strength of high speed airflow generated after gas was driven into target cabin by two-stage light-gas gun.The effectiveness of this micro particles launch method was verified by experiments.The damage characteristics of several typical materials micro particles impacted glass target were obtained,and the impact process of micro particles,the influence of impact quantity and velocity of particles on the formation of adsorption layer was analyzed.Experiments of four kinds of typical materials micro particles impact glass target were carried out using micro particles launch technology to get damage characteristics of micro particles impact glass target for different materials,and affecting factors of the damage characteristics of glass target were analyzed.The impact forms of micro particles were obtained by experiments using titanium nitride micro particles impacted coating target.The effect of impact quantity and velocity of micro particles on damage characteristics was investigated,and the experiment parameters of forming adsorption layer were obtained.In order to lay the foundation for analyzing the formation mechanism of adsorption layer,the study of damage pattern and damage process of glass target caused by particles independent impact was carried out using experiment and numerical simulation.Experimental results of plasma drive accelerator showed that damage model of aluminum oxide,nitride titanium and silver particles is forming impact crater in velocity range in this paper.The numerical simulation model of single particle impacted glass target and copper target was established to get damage mode of aluminum oxide which formed impact crater,and damage mode of copper target impacted by copper particle in cold spraying technology formed impact crater and combined with copper particle.Experiments and numerical simulations showed that the damage mode of glass target caused by independent impact behavior was impact crater.It can be preliminarily determined that the adsorption layer formed under certain conditions of micro particles swarm impacting on glass target is not caused by the direct combination of particles and glass target after impact.The distribution characteristic of friction force was obtained through friction test of adsorption layer,and geometric and physical property of adsorption layer was analyzed as well,and a numerical simulation model of process of particles swarm impact glass target was established based on discrete element method to explore the formation mechanism of the adsorption layer morphology.Using friction as the characterization method of adsorption layer characteristics,then the friction of adsorption layer formed by nitride titanium particles impacting glass target under different experimental parameters was tested,and the friction test and analysis of micro particles impacting on aluminum alloy target are carried out as a contrast,and the frictional force distribution characteristic was obtained.On this basis,the geometry and physics distribution characteristic of adsorption layer was obtained.The numerical simulation model of process of particles impacted glass target was established by using the discrete element method with the titanium nitride particles as an example,and the validity of the model was verified through experiment contrast.Simulation results show that the formation of adsorption layer was the result from motion model of particles impacted glass target which involves reciprocating “impact–bounce”,accumulation and radial movement,and this mode was the key to the formation of adsorption layer.In conclusion,for the damage characteristics of micro particles impact glass target,a micro particles launch technology based on two-stage light gas gun has been proposed,and experiments of micro particles swarm impact glass target were carried out,and put emphasis upon carrying out related research about characteristic of forming adsorption layer.Based on the damage model of glass target caused by independent impact of particles and the distribution characteristics of adsorption layer,referencing mechanism of particles combine with the matrix in cold spraying,and establishing numerical simulation model of micro particles impact glass target,the motion pattern of micro particles swarm impact glass target are obtained,and the formation mechanism of adsorption layer morphology was discussed.The research results of this paper will provide technical reference for damage assessment of spacecraft optical parts and space defense technology.