复杂环境下曲面接触扭转微动磨损机理研究

The damage induced by dual-rotary fretting are presented in a large number tribo-pairs which have rotary relative motion. Dual-rotary fretting causes local fatigue crack initiation in some parts, and the service life is greatly reduced. A great deal of failure cases e.g. medical implant devices, nuclear power equipment, marine engineering equipment and weapon equipment system indicated that the dual-rotary fretting is one of the main cause. The related research is rare, and there is an urgent need for the research of the mechanism and control method of the dual-rotary fretting wear. This study will combine the numerical simulation and experiment method. A new fretting test device will be designed and manufactured, and it can realize the dual-rotary fretting under curved surface contact model in many complex environment. We will simulate complex experimental conditions (e.g. high temperature, vacuum), and reveal the damage influencing factors from angular displacement, stress level, temperature, medium environment, oxidation atmosphere. The friction oxidation and the third body behavior will be explored, and a theory model of dual-rotary fretting wear and it’s protection criterion will be established. The tribology design thought will be considered, which through changing the interface contact mode, material properties, design of surface texture, etc. This study will build a method to slow down the fretting damage occurred in curved surface. And the research results will provide theoretical support and technical reference.

扭转微动损伤广泛存在于有回转相对运动的摩擦副中，它导致零部件磨损或局部疲劳裂纹萌生与扩展，使服役寿命大为降低，如大量的医学植入器件、核能装置、海洋工程装备、武器装备等领域失效案例。目前相关研究鲜见，急需开展扭转微动磨损机理及其控制方法的研究。本研究拟采用数值模拟与试验相结合的方法，研制新型高温真空扭转微动磨损试验装置，实现曲面配合条件下的扭转微动；模拟各种复杂实验条件，揭示不同倾斜角、角位移、应力水平、温度、氧化气氛条件下的损伤机理和影响因素。重点考察其摩擦氧化和第三体行为，建立扭转微动磨损的理论模型，提出扭转微动磨损损伤防护准则。并运用摩擦学设计思想，通过改变界面接触方式、材料性质、设计表面织构，改变材料匹配等手段探讨减缓扭转微动损伤的途径，为减缓曲面发生微动磨损破坏提供理论支持和技术参考。

本研究针对联合基金的要求，和参研单位人员一道研发了新型高温真空扭转微动磨损试验机，并开展了针对渗氮处理的钛及钛合金表面开展扭转微动磨损试验和贫铀的切向微动磨损试验。对真空扭转试验机进行升级，并且针对贫铀及其Ti/TiN多层涂层在不同载荷条件、不同频率条件及不同气氛条件下，进行了切向微动磨损试验。进行了针对304不锈钢及其Al2O3涂层在不同的载荷和角位移幅值下及不同的粗糙度条件下的扭动微动磨损试验。.研究结果发现（1）氮离子注入浓度和角位移幅值显著影响扭动微动运行和损伤行为。随着氮离子浓度增加，扭动微动运行边界呈现向小角度位移，中心轻微磨损区减少。（2）贫铀在在氧气环境下的磨损机理为氧化磨损和磨粒磨损；大气环境下为氧化磨损、剥层和磨粒磨损；氩气环境下也出现裂纹，且伴随剧烈的粘着磨损；低真空环境主要为粘着磨损；高真空环境下主要为机械剥除作用，产生大量裂纹。（3）贫铀基体和多层涂层的磨损率均随着的载荷的增加而降低，多层涂层的存在可以有效降低贫铀的磨损量和磨损率。（4）研究了粗糙度对扭动行为的影响，结果显示随着粗糙度的降低，接触的状况得到改善，扭矩的数值下降。.研究结果对贫铀球的加工、保护、储存提出了部分建议。