In the process of manufacturing the world’s largest silicon carbide(SiC)aspheric mirror,the primary difficulties are mirror blank preparation,asphere fabrication,and testing,as well as cladding and coating.Specifical...In the process of manufacturing the world’s largest silicon carbide(SiC)aspheric mirror,the primary difficulties are mirror blank preparation,asphere fabrication,and testing,as well as cladding and coating.Specifically,the challenges include the homogeneity of the complicated structure casting,accuracy and efficiency of the fabrication process,print-through effect,fidelity and precision of test procedure,stress and denseness of cladding process,the dynamic range of interferometric measurement,and air turbulence error due to the long optical path.To break through such a barrier of difficulties,we proposed the water-soluble room temperature vanishing mold and gel casting technology,homogeneous microstructure reaction-formed joint technology,nano-accuracy efficient compound fabrication,gravity unloading technology,high-denseness low-defect physical vapor deposition(PVD)Si-cladding technology,test data fusion method,and time-domain averaging method,etc.Based on the proposed technologies and methods,we have accomplished the world’s largest SiC aspheric mirror with a size of φ4.03 m.The impressive performance of the SiC aspheric mirror is validated by the characteristics of the fabricated SiC aspheric mirror.The aerial density of the SiC blank is less than 120 kg/m^(2),surface shape test accuracy is better than 6 nm RMS,thickness inhomogeneity of the cladding layer is less than 5%,and the final surface figure error and roughness are 15.2 nm RMS and 0.8 nm RMS,respectively.展开更多
基金financial support by Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDJ-SSW-JSC038)Bureau of International Cooperation,Chinese Academy of Sciences(181722KYSB20180015)+2 种基金Jilin Province Science and Technology Development Plan Project Mission Statement(20200401065GX)National Natural Science Foundation of China(62127901,61805243,11803037,61975201,11903035,11903036,62005278,12003035,12003034,62075218,and 12103054)Youth Innovation Promotion Association,Chinese Academy of Sciences(2019221,2021215,and 2022213).
文摘In the process of manufacturing the world’s largest silicon carbide(SiC)aspheric mirror,the primary difficulties are mirror blank preparation,asphere fabrication,and testing,as well as cladding and coating.Specifically,the challenges include the homogeneity of the complicated structure casting,accuracy and efficiency of the fabrication process,print-through effect,fidelity and precision of test procedure,stress and denseness of cladding process,the dynamic range of interferometric measurement,and air turbulence error due to the long optical path.To break through such a barrier of difficulties,we proposed the water-soluble room temperature vanishing mold and gel casting technology,homogeneous microstructure reaction-formed joint technology,nano-accuracy efficient compound fabrication,gravity unloading technology,high-denseness low-defect physical vapor deposition(PVD)Si-cladding technology,test data fusion method,and time-domain averaging method,etc.Based on the proposed technologies and methods,we have accomplished the world’s largest SiC aspheric mirror with a size of φ4.03 m.The impressive performance of the SiC aspheric mirror is validated by the characteristics of the fabricated SiC aspheric mirror.The aerial density of the SiC blank is less than 120 kg/m^(2),surface shape test accuracy is better than 6 nm RMS,thickness inhomogeneity of the cladding layer is less than 5%,and the final surface figure error and roughness are 15.2 nm RMS and 0.8 nm RMS,respectively.
