Effect Of Solid Particle Erosion On Surface Roughness And Transmittance Of Polymer Film

Polyimide film(Kapton)and Fluorinated ethylene propylene film(FEP)have good space environment resistance and are widely used in aerospace systems.Sandblasting experiment was used to simulate the solid particle erosion process in the space environment,and the impact resistance of Kapton and FEP films was tested.This dissertation focuses on the variation of surface roughness and optical transmittance of Kapton and FEP films with impact time(t),impact mass(q·t),impact momentum per unit time(q·v_p),and impact strength(q·t·v_pⁿ),n is the index of particle velocity)over the entire life under sand impact.The empirical models are also given.Research indicates:Firstly,obvious macro-deformation and micro-morphological changes appear after sand impact.The impact of the core flow in the wind-sand flow forms"crater"and work hardening effect on the film surface.Film breaks when the accumulated plastic strain reaches a critical value.The micro-morphological changes are related to cutting,extrusion and forging of sand impact.Secondly,the impact time of Kapton film is 2.7 times longer than that of FEP film under three impact conditions,and the maximum is 6 times.This means Kapton film has significantly better impact resistance than FEP film.With the increase of impact time,impact mass and impact strength,the surface roughness increases exponentially,while the transmittance decreases in the form of a negative exponential function.The surface roughness of Kapton and FEP films increases by 1400%and 700%,and the transmittance decreases by 80%and 60%,respectively.Through the correlation analysis between surface roughness and transmittance,it is revealed that the decrease of transmittance is positively correlated with the increase of surface roughness,indicating that the increase of surface roughness is the key factor leading to the decrease of transmittance.Furthermore,the empirical characterization models of surface roughness and transmittance as a function of impact strength are established.Finally,although the transmittance of FEP film to near-infrared,visible and ultraviolet light is slightly higher than that of Kapton film under the same impact conditions,Kapton film can withstand longer impact time,more impact mass and higher impact strength over the entire life.Therefore,compared with FEP film,Kapton film has stronger impact resistance and is more suitable for use in dust environment.