液相等离子体电解耦合法构建橡塑模具抗粘附表面的理论与方法研究

The defects of surface tear, rupture of the rubber and plastic products as well as the shortening die service life are induced by excessive adhesion force. Adhesion phenomenon are caused by mechanical occlusion, physical binding and chemical reaction between rubber and plstic molds and parts. The traditional preparation methods of anti-adhesion surface always ignore the composite coupling relation between surface roughness, surface topography and surface chemical group. In view of this, liquid plasma electrolytic coupling methold is proposed to build wear-reistant surface based on bionic principles of anti-adhesion. With the help of electrochemical anodic oxidation (Reducing the macroscopic surface roughness), liquid micro-plasma polishing corrosion (Constructing concave units of unsmoothed microstructure) as well as the diffusion penetration of dielectric element on the electrode surface (generating of surface functional layer), based on the reasonable match and control of thermal effect and diffusion effect. On the basis of analysis of energy coupling mechanism and mobile law of the reaction interface, a prediction model is established to describe the relationship between the main process parameters such as field characteristics,energy density of micro-plasma and anti-adhesion quality, and methods are grasped to control the width, depth and distribution of micro-topography of the pit of non-smooth unit. Consequentially, it is comprehensively evaluated for the anti-adhesion performance to seek the reasonable process conditons, with making overall plans for the function, the efficiency, the operational effectiveness and other factors. Consequentially, it is provided to the foundation for the final build the simple and effective, low-cost anti-adhesion theory and methods of rubber and plastic mold surface.

粘附力过大是导致橡塑制品表面撕裂、破裂等缺陷以及模具使用寿命降低的主要问题，造成制品与模具表面粘附的原因是机械咬合、物理结合和化学反应，而抗粘附表面的传统制备方法大多将原本存在复合耦合关系的表面粗糙度、表面微观形貌、表面化学组分割裂开来进行单独仿制。鉴于此，提出利用液相等离子体电解耦合法，借助电化学阳极氧化反应（降低宏观表面粗糙度）、液相微等离子体抛蚀（构建凹坑非光滑单元体微观结构）以及电介质元素在电极表面上的扩散渗透（生成表面功能层）等作用，通过对化学效应、热效应和扩散效应的有序、合理控制，在金属基橡塑模具上构建易于脱模的耐磨抗粘附表面。将在研究能量耦合机制、反应界面移动规律的基础上，建立主要工艺参量与抗粘附质量之间关系的预测模型，寻求兼顾性能与成本的工艺条件，掌握凹坑非光滑单元体微观几何形貌的宽度、深度和分布的控制方法，为最终构建简单有效、成本低廉的橡塑模具抗粘附理论与方法奠定基础。

针对橡塑模具服役过程中易粘污而频繁清洗的问题，本项目基于仿生耦合原理，利用液相等离子体电解加工过程中存在热效应、化学效应、扩散效应的特点，分别借助微等离子体抛蚀、电化学阳极氧化和电化学沉积等作用，最终建立了获取橡塑模具抗粘附表面的技术基础，形成了较为完备的抗粘附表面加工理论体系和工艺规范。在研究基本要素对模具表面抗粘附性能的影响规律方面，本项目综合比较了高速切削法、电化学光整加工法、化学刻蚀法、电化学阳极氧化法、等离子体喷涂法、复合电刷镀法等加工技术在获取模具抗粘附性能的各自特点，并结合模具抗粘附性能相关的分析，提出了获取模具抗粘附表面的重要条件和表征方法的手段。在构建橡塑模具抗粘附表面基底方面，本项目提出利用液相等离子体电解耦合法中的微等离子体形成二元阶层微观形貌中的微米凹坑结构，提出利用电化学阳极氧化制备二元阶层微观形貌中的纳米凸起结构，揭示了液相等离子体电解耦合加工中热效应和化学效应与模具抗粘附表面基底间的内在关系。在制备橡塑模具抗粘附表面功能层方面，本项目提出利用电化学沉积纳米SiO2/Ni结合含氟偶联剂化学沉积作用，在具有二元阶层微观结构的模具表面基底上，制备出具有低表面能的SiO2/Ni复合功能层，在降低模具表面润湿性、提高表面的抗粘附性能的同时，增强模具表面的耐磨性能。本项目通过控制液相等离子体电解耦合法过程中的热效应、化学效应和扩散沉积效应，使表面功能层与表面粗糙度、表面微观结构协同作用，最终在橡塑模具上制备出耐磨抗粘附性能的表面，该方法对保持橡塑模具芯部原有成分和性能、赋予模具表面特殊使用性能、降低粘附几率、减少模具清洗次数、提高模具使用寿命具有一定的参考价值。