Ultraprecision error compensation turning for high-gradient aspheric surface based on B-axis platform

High-gradient aspheric elements need to meet the requirements of both high-gradient aspheric characteristics and a streamlined shape in aerodynamics.The shape characteristics of high-gradient aspheric surfaces bring great challenges to machining.Aiming at hard machinability of single-point diamond turning high-gradient optical opponents, an ultraprecision XZB axes single-point diamond turning technique was presented based on rotation B-axis platform.Through analysing the traditional XZ axes turning method, the new XZB axes turning process was proposed to fabricate a high-gradient aspheric surface.The influences of setting errors and cutting edge of arc lathe tool in Y-direction and X-direction on profile accuracy were analysed for correcting the new tool position.The compensation turning method of axisymmetric surface was presented.An error compensation turning experiment of copper was proposed and carried out to obtain a high-gradient aspheric surface.After three time cycles, the profile accuracy was improved from PV 590 nm to PV 103 nm.