铝基复合材料强力旋压成形颗粒/基体协调变形机制及损伤行为的研究

Particle reinforced aluminum matrix composites have excellent performance such as high specific stiffness, high specific strength and high dimensional stability,and tubes of composites have good application prospects in the field of high performance and lightweight of space technology and advanced weapons systems. It is very difficult to produce tubes of composites by means of power spinning due to low ductility and poor deformability of composites. Therefore, it is urgent to investigate some basic problems such as the mechanism of coordination deformation between particles and the matrix and damage behavior during power spinning of composites. The coordination deformation between particles and the matrix during power spinning of aluminium matrix composites is studied as a starting point for this project. The main line of plastic processing is to take the initiative to control the macro or microstructural defects. A study methods is to combine numerical simulation, experiment and theoretical analysis. The purpose of the study is to reveal the coordination deformation mechanism between particles and the matrix during spinning process of composites; to understand the action of the coordination deformation in mining potential plastic deformation and improving the ability of forming; to reveal the interaction actions and mutual influence laws between coordination deformation and micromechanical damage evolution; to clarify the coordinate deformation inhibiting or slowing the micromechanical damage and improving the forming limit; to reveal the damage mechanism of spinning for composites; to obtain the forming limit and optimize the process. The research results will provide a scientific basis for the optimization design of manufacturing process of the precision plastic forming for the composites tubes with integrating regulation on the shape and performance and also lay the foundation for the stable production and engineering applications of high-precision, high-performance and lightweight tubes.

颗粒增强铝基复合材料具有高比刚度、高比强度、高尺寸稳定性等优异性能，其管件在空天技术和先进武器系统等领域高性能化、轻量化方面具有良好的应用前景。但复合材料塑性差韧性低，管件强旋制造困难，亟需研究复合材料强旋成形颗粒/基体协调变形机制及损伤行为等关键基础问题。本项目以颗粒/基体协调变形为切入点，以主动控制宏/微观缺陷为主线，采用数值模拟、试验和理论分析三者有机结合的方法，研究揭示复合材料强旋成形颗粒/基体协调变形机制，明确颗粒/基体协调变形在挖掘塑性变形潜能和提高成形能力方面的作用；揭示颗粒/基体协调变形与细观损伤演化的交互作用和相互影响规律，探明颗粒/基体协调变形对抑制、减缓细观损伤和提高成形极限的作用；揭示复合材料强旋损伤机理，确定成形极限，优化工艺；为复合材料管件精确成形成性一体化制造工艺优化设计提供科学依据，为高精度、高性能轻质管件稳定生产和工程应用奠定基础。

铝基复合材料具有高比刚度、高比强度、高尺寸稳定性等优异性能，其管件在空天技术和先进武器系统等领域高性能化、轻量化方面具有良好的应用前景。但复合材料塑性差韧性低，管件强旋制造困难。.TEM观察研究发现，铝基复合材料旋压过程中颗粒/基体通过引入几何必须位错、动态回复和动态再结晶及颗粒转动进行协调变形，以动态回复和动态再结晶协调变形为主，减缓应力集中，抑制微观损伤，提高复合材料旋压成形能力。变形温度越高、应变速率较低，复合材料的协调变形能力越强，断裂应变也随之升高。低温、高应变速率旋压时，颗粒断裂和界面脱粘等细观结构的损伤，逐渐演变为宏观缺陷，旋压开裂机制为以韧性断裂为主，脆性断裂并存的混合断裂。颗粒/基体协调变形研究和定量表征十分困难，正在深入研究。.基于连续损伤力学理论，考虑变形温度和应变速率的影响，建立了颗粒增强铝基复合材料高温变形过程中的损伤演化模型。利用弹性模量法进行高温多道次拉伸实验，得到了不同变形条件下的损伤演化曲线，求解的损伤演化模型参数为A(Z)=2.22769-0.09438lnZ+0.00238ln2Z，断裂的判据为DC(Z)=0.50915-0.00577lnZ。.建立了耦合损伤演化铝基复合材料旋压有限元模型，分析了旋压温度、减薄率和进给比对复合材料强力旋压损伤值的影响，损伤值随温度的升高而降低，随减薄率的增加而升高，随进给比的增加而升高，揭示了工艺参数对损伤的影响规律。构建了旋压成形极限图（损伤值的三维曲面图），通过成形极限图可以选择复合材料旋压的安全参数范围，避免旋压宏微观缺陷的产生，通过实验对数值模拟的预测进行验证，结果较为吻合，明确了旋压工艺窗口。.本项目提出结合加工图、成形极限图、颗粒/基体协调变形、数值模拟和压缩试验模拟的方法，优化复合材料旋压工艺，有助于解决铝基复合材料（低塑性难变形材料）旋压瓶颈，保证产品质量，为高性能轻质管件精确成形成性一体化制造技术提供理论依据和工艺优化方法，为高精度、高性能轻质管件稳定生产和工程应用奠定基础，对铝基复合材料的应用和解决实际问题具有重要意义。.此外，在本项目资助下，将高效塑性变形、大剪切应变、大应变梯度、高应变速率及大应变速率梯度相结合，提出旋轧碾压（旋碾）塑性变形新技术，可实现大尺寸金属构件表层微纳米梯度组织的工业规模化、高效、环境友好、可控制备，初见效果。