大尺寸反射镜高精度光学镜面Ni-P过渡层的制备方法

Preparation of Ni-P Alloy Transition Layer of High-Precision Optical Surface for Reflection Mirror with Large Size

为了解决高精度光学系统中铝合金、铍反射镜易钝化、难加工的问题,采用自催化镍-磷合金作为过渡层后进行抛光的方法得到了高精度光学镜面.采用该方法所得到的镍-磷合金过渡层厚度为85μm,磷质量分数为11.88%,镀层显微硬度为730MPa.镍-磷合金过渡层与反射镜结合牢固、耐蚀性较好,可通过±200℃热震试验及96h中性盐雾试验检测,适用于进行古典法抛光.经抛光后反射镜面形精度均方根值(RMS)为0.049λ(面形检测波长λ为0.6328μm),表面疵病等级为Ⅳ级,能够满足光学系统的要求.

In order to obtain a high-precision optical surface, Ni-P alloy transition layer was prepared on Al alloy and Be reflection mirror by an electroless plating technique, which showed that a Ni-P alloy coating could be obtained on Al reflection mirror in optical system of 85 μm in thickness,730 MPa in micro-hardness,and 11.88% of P concentration. With classical polishing technologies, fine surface can be obtained on Ni-P alloy coating as follows： surface figure root mean square （RMS） of 0.049λ（λ = 0.632 8μm） and surface imperfection of Ⅳ. The results of thermal shock test and neutral salt spray test show that the electroless Ni-P transition layer adheres well to the Al alloy and Be reflection substrate and has good corrosion resistance, and the transition layer is suitable for optical system.