Liao Qiuyan, Ding Fei, Chen Zhigao, Li Duo, Wang Bo
College of Mechanical Engineering, Harbin Institute of Technology, Harbin 150001, China.
Micromachines (Basel). 2023 Aug 26;14(9):1666. doi: 10.3390/mi14091666.
The eXTP (enhanced X-ray Timing and Polarization) satellite is a prominent X-ray astronomy satellite designed primarily for conducting deep space X-ray astronomical observations. The satellite's scientific payload consists of X-ray focusing mirrors. In order to fulfill the requirements of weight reduction and enhanced effective area, the thickness of mirrors is reduced to the sub-millimeter range and a multi-layer nested structure is employed. Manufacturing mirrors poses a significant challenge to both their quality and efficiency. The present research investigates the optimal replication process for mandrel ultraprecision machining, polishing, coating, electroforming nickel, and demolding. It analyzes the factors contributing to the challenging separation and the inability to release the mirror shells. Additionally, an automatic demolding device is developed, and the X-ray performance of the replication mirrors is verified. The fabrication process flow of the mirrors was initially introduced. To ensure the easy release of the mirror shells from the mandrels, a layer of diamond-like carbon (DLC) was applied as a release layer between the Au and NiP alloy. The adhesion strength of Au-C was found to be significantly lower than that of Au-NiP, as demonstrated by both molecular dynamic simulation and tensile testing. The development of an automatic demolding device with force feedback has been successfully completed. The reduction in the half-power diameter (HPD) of the mirror from 48 inches to 25 inches is an improvement that surpasses the production target.
增强型X射线计时与偏振（eXTP）卫星是一颗主要用于进行深空X射线天文观测的杰出X射线天文卫星。该卫星的科学有效载荷由X射线聚焦镜组成。为了满足减重和提高有效面积的要求，镜子的厚度被减小到亚毫米范围，并采用了多层嵌套结构。制造镜子对其质量和效率都构成了重大挑战。本研究探讨了芯轴超精密加工、抛光、镀膜、电铸镍和脱模的最佳复制工艺。分析了导致分离困难和镜壳无法脱模的因素。此外，还开发了一种自动脱模装置，并验证了复制镜的X射线性能。最初介绍了镜子的制造工艺流程。为确保镜壳易于从芯轴上脱模，在金和镍磷合金之间涂覆了一层类金刚石碳（DLC）作为脱模层。分子动力学模拟和拉伸试验均表明，金-碳的粘附强度明显低于金-镍磷。已成功完成了具有力反馈的自动脱模装置的开发。镜子的半功率直径（HPD）从48英寸减小到25英寸，这一改进超过了生产目标。
