双变激振及控制的振动纳米粉碎理论与方法研究

Micro-nano super-hard particle has the advantages of both micro-nano particle and super-hard particle. It has a great application potential in many fields such as aerospace and military equipment. Mechanical method has significant technical and economic advantages in preparation methods while vibration mill has a high quality in mechanical method. However, at present, only some ultramicro particles can be gained when these particles are prepared. The particle size 0.5μm is called "the limit" in this field. In order to solve these technology bottlenecks such as hard aggregation and no-refinement, the double variable excitation and control method with variable vector and vibration frequency are put forward. Vibration model is built. Mill parameters are also optimized. The change characteristics of high vibration intensity are given. Hybrid algorithm is designed based on the fuzzy reasoning and data mining. A predictive model and control system of time series and neural network are built, and the evidence of transboundary predictive control on high vibration intensity is gained. Based on the dynamics numerical simulation of the vibration mill, the nonlinear vibration and response features of double variable excitation are researched. According to the numerical simulation of medium flow, the dynamics characteristics of medium flow are researched such as velocity field, force chain field and collision force. Through the mentioned "three-methods" and information fusion, coupling characteristics among high vibration intensity, aggregation breaking and particle refinement are found out, and the best change rules of vibration intensity can be given. Vibration nano comminution theory and method research based on the double variable excitation and control are formed. It has great theoretical and practical application value, not only in reducing the grinding limit for super-hard and medium hard particles, but also in reducing the energy comsumption during the preparation of low-cost and high-quality particle.

纳米超硬颗粒兼具纳米与超硬颗粒的双重优势，在航空航天、军工器械等众多领域，应用潜力巨大，机械法在诸制备法中具有工艺、经济优势，振动磨在机械法中具有质量优势，但目前仅为部分超微，达0.5μm被业内称为"极限"。针对超微颗粒硬团聚、不细化等技术瓶颈，提出变矢径变振频的双变激振及控制理论方法，建立其振动模型，优化机构参数，研究高振强特性，基于模糊推理与数据挖掘的混合算法，构建时间序列/神经网络组合预测模型及控制系统，取得高振强越界预测控制实证；基于振动磨动力学数值仿真，研究双变激振的非线性振动响应；基于磨介流动力学数值模拟，研究磨介流速度场、力链场、撞击力能等动力学特性；通过上述"三法"互动信息融合实证，揭示高振强与聚团破碎、颗粒细化特性耦合机理，给出振强最佳变化规则，形成双变激振及控制的振动纳米粉碎理论与方法，对于超硬、中硬颗粒降低粉碎极限及能耗的高品质低成本制备，具有重大理论与工程应用价值。

针对目前国内外振动磨超微颗粒硬团聚、不细化的技术瓶颈，研发具有变当量矢径功能的二级偏块激振器振动磨，优化偏块质径比，改进振源设置，使磨机能产生具有一定频次、频幅跃动变化的强非线性混沌态；研制的双变激振控制系统，在新型磨机产生具有一定频次的高振强及大振幅状态下,能实现振强振幅的越界超前预测控制；基于Adams、Matlab的振动磨动力学数值仿真，研究系统的非线性振动响应，获得质体运动线图、连续功率谱、相轨图、Poincare图、Lyapunov指数图等图像数据，形成筒体激振参数变化的数据流；实施基于EDEM、PFC2D/3D的磨介流动力学数值模拟，研究磨介流场的动力学特性，获得典型磨介速矢图、力链场、能量场、筒壁受力曲线等动力学数值图像，形成磨介流流型流向、撞击力能等动力特性模拟数据流；将仿真模拟数据流与实验、检测、控制的数据流互动融合，构成信息融合的研究结果，再通过实验来验证上述方法的有效性，检测结果表明，双变激振与控制方法使金刚石粒度均值较目前的0.5μm细化至0.2μm以下，实现了降低粉碎极限的目标，向进入纳米跨近了一大步；研究过程发表的系列学术论文和专利成果，初步形成了双变激振与控制的基本理论和方法，研究成果对于破解超硬高硬粉体硬团聚和不细化的技术瓶颈，具有重要实际应用价值；对于人们从事现有各种超微粉体实现低成本、高质量的振动制备，亦具有有益的借鉴和参考。