Research On The Relation Between Rotational Speeds Of Spin-cast And Aspherical Forming Regulation

The manufacture of aspherical mirrors is not only a difficult problem in the field of advanced optical manufacturing,but also one of the important technologies in manufacturing.Traditional aspherical optical element processing methods have the disadvantages of high material cost and long processing cycle.There are many methods for processing existing aspherical optical elements and have been applied to actual production,such as computer-controlled small grinding head processing methods,stress disk processing methods,and optical lens molding techniques,but these methods are directly performed on materials.The processed and processed materials generally have a surface destructive layer,causing stress concentration and glass cracking.These methods are mainly applied to small and medium-sized aspherical parts and still cannot meet the production and processing of large-diameter aspherical mirrors.In order to avoid the above problems,a new processing technology-the Spin-cast is proposed;that is,the glass melt is rotated at a certain rotation speed in a high-temperature melting furnace until the upper surface of the glass melt reaches a stable state.Annealed and cooled,an aspherical mirror embryo is finally formed,which forms the basis for subsequent polishing.Centrifugal rotation speed is the main factor that determines the aspherical surface forming.In this paper,the mathematical model of the centrifugal rotation speed and surface forming law in the forming process is established.The simulation of the H-K9 L optical glass centrifugal casting process is performed using Abaqus finite element analysis software to determine the relevant experimental parameters,and according to the parameters obtained three sets of centrifugal casting experiments with different rotation speeds and different forming temperatures,the use of related instruments to detect the surface contour profile and roughness of the forming aspheric surface to verify the correctness of the mathematical model,the validity of the simulation analysis and aspherical mirror centrifugation The feasibility of casting technology.