The alignment of the glass elements from radiation-resistant optical glass K-208 for thermal control coatings of spacecraft

Currently, space technology as a passive means for ensuring the thermal regime successfully applied optical coating (elements of thermal control coatings) based on ultrathin (thickness 150 µm) elements of optical radiation-resistant glass К208. The article discusses the process of making glass elements for thermal control coatings includes the following stages: - the action of pulling the glass tape block heated to a high temperature plastic state of the glass through a die steel;- dimensional cutting of glass tape, with the assistance of scraborough diamond tool;- process thermal plastic alignment elements, carried out in a furnace by heating to a temperature of plasticity of the glass under load. The process of the extrusion of highly plastic block large dimension leads to difficulties in ensuring flatness of pulling the glass tape. As a rule, the shape of the glass tape has a convex shape.To provide the required deviation from flatness, the technology of thermal plastic deformation under load of the glass elements. The process of alignment of the convex glass elements, the selected temperatures and time of exposure, allows minimal deviation from flatness (up to 10 µm).Measurements of deviations from flatness of the glass elements before and after the alignment process with the help of a profilometer-profilograph 252 "Caliber". The measurement results confirm the effectiveness of the selected technology alignment.The alignment process allows to obtain thin elements of K-208 glass with minimal deviation from flatness, which allows them to apply the elements of thermal control coatings of spacecraft.