面向钨表面抗辐照改性的剪胀抛光方法研究

Aiming at the problem that poor surface quality of tungsten used in fusion reactor will aggravate the radiation damage of hydrogen/helium and affect the service life of fusion reactor, this project proposes a new shear dilatancy polishing method which can improve the radiation resistance of tungsten surface: prepare a flexible fixed abrasive tool by the viscoelastic material with non-newtonian fluid characteristics, in order to enhance the control of abrasive particles and improve the stress evenness and contact pressure on the workpiece surface based on the shear dilatancy and solidification effects in the polishing process, finally achieve high efficiency and high quality polishing. By means of theoretical analysis, numerical simulation and experimental study, this project intends to prepare a flexible fixed abrasive tool, reveal the shear dilatancy and solidification mechanism, and establish a method for testing and evaluating the characteristics of the flexible fixed abrasive tool; reveal the action mechanism and material removal mechanism between the abrasive tool and workpiece surface, determine the main control factors for the polishing process; investigate the influence mechanism of the changed surface quality to the radiation resistance of tungsten after the shear dilatancy polishing, and finally propose a technological specification on tungsten used in fusion reactor after shear dilatancy polishing. The development of this project is expected to develop a new high-efficiency and high-quality polishing method, which has important scientific significance and engineering value for enriching ultra-precision abrasive processing technology.

针对核聚变堆用钨表面质量差会加剧氢/氦辐照损伤，影响聚变堆使用寿命的问题，项目提出一种可提升钨表面抗辐照性能的剪胀抛光新方法：采用具有非牛顿流体特性的粘弹性材料制备柔性固着磨具，通过抛光过程中产生的剪切膨胀和固化效应，以增强磨粒的把持力、提高工件表面的受力均匀性和抛光正压力，实现高效高质量抛光。本项目借助理论分析、数值模拟和实验研究，研制柔性固着磨具，揭示其剪切膨胀及固化机制，并建立柔性固着磨具特性检测评价方法；揭示磨具与工件表面的作用机制及材料去除机理，确定抛光过程的主要控制因素；探究剪胀抛光后钨表面质量变化对其抗辐照性能的影响机制，最终提出核聚变堆用钨剪胀抛光的工艺规范。本项目的开展有望发展一种高效高质量抛光新方法，对丰富超精密磨粒加工技术具有重要的科学意义和工程应用价值。

受控热核聚变能被认为是能够有效解决未来能源问题的主要途径之一。针对核聚变堆用钨表面质量差会加剧氢/氦辐照损伤，影响聚变堆使用寿命的问题，项目提出一种可提升钨表面抗辐照性能的剪胀抛光新方法：采用具有非牛顿流体特性的粘弹性材料制备柔性固着磨具，通过抛光过程中产生的剪切膨胀和固化效应，以增强磨粒的把持力，提高工件表面的受力均匀性和抛光正压力，实现高效高质量抛光。借助理论分析、数值模拟和实验研究等手段，项目研制了柔性固着磨具，揭示了其剪切膨胀及固化机制，并建立了柔性固着磨具特性检测评价方法；揭示了磨具与工件表面的作用机制及材料去除机理，确定了抛光过程的主要控制因素；探究了抛光后钨表面质量变化对其抗辐照性能的影响机制。项目设计并制备一种剪胀垫，将剪胀垫用于钨剪切膨胀抛光，通过与游离磨料抛光的单因素对比试验，验证了剪切膨胀抛光的可行性及有效性。结果表明，剪切膨胀抛光的材料去除率明显高于游离磨料抛光。高压高转速下，在转速为180 r/min, 压强为468 kPa时，加工效率提升27.4%，Ra相对减小了48%。最终确定了剪切膨胀抛光优化参数，即金刚石磨料粒径0.5 µm，柔性固着磨具中磨粒浓度为30 wt.%，抛光转速120 r/min，抛光压强468 kPa。高能量低剂量氢辐照条件下，样品表面质量越高，表面粗糙度越小，TDS脱附曲线的峰越低，氢滞留越少，抗氢辐照性能更好。本研究为超精密加工提供一种新的抛光技术和理论体系，研究成果也为未来核聚变堆用钨的机械加工提供了理论参考。