(1. 中南大学 粉末冶金国家重点实验室，长沙 410083；
2. 香港城市大学 材料科学与工程系，香港 999077)
摘 要: Ti基金属-金属复合材料具有良好的强度和塑性等综合性能。采用扫描电子显微术(SEM)、X射线衍射(XRD)、材料力学性能试验、分离式霍普金森压杆(SHPB)、MATALAB软件等分析技术研究了W颗粒增强Ti基金属-金属复合材料(Ti-W)在准静态和动态下的力学行为。结果表明：Ti-W复合材料具有β-Ti相和β-W相组成的双相异质结构；当W元素含量大于25%(摩尔分数)时，组织中析出细小的富W相。Ti-W复合材料在准静态下的最高屈服强度和极限强度可达1567 MPa(Ti-30W)和1726 MPa(Ti-30W)；动态下最高屈服强度和极限强度可达2148 MPa(Ti-15W)和2908 MPa(Ti-30W)。因此，Ti-W复合材料具有明显的应变速率强化效应。比较了改进的Johnson-Cook(JC)本构模型和Back-Propagation(BP)神经网络模型对Ti-W复合材料力学行为的适用性，发现BP神经网络能更好地描述Ti-W复合材料在准静态和动态下的力学行为。
关键字: Ti-W金属-金属复合材料；应变速率强化；Johnson-Cook(JC)本构模型；Back-Propagation(BP)神经网络模型
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong 999077, China）
Abstract:Ti matrix metal-metal composites exhibit good comprehensive properties such as strength and plasticity. The quasi-static and dynamic behavior of W particle reinforced Ti matrix metal-metal composites(Ti-W) were investigated by scanning electron microscopy(SEM), X-ray diffractometry (XRD), material mechanical properties test, split Hopkinson pressure bar (SHPB) and MATALAB software. The results show that Ti-W composites exhibit a dual phase heterostructure composed of β-Ti and β-W. When the content of element W in the composite is greater than 25% (mole fraction), fine W-rich phase is precipitated in the tissue. The maximum yield strength and ultimate strength of Ti-W composites can reach 1567 MPa (Ti-30W) and 1726 MPa (Ti-30W) under quasi-static condition. The maximum yield strength and ultimate strength can reach 2148 MPa (Ti-15W) and 2908 MPa (Ti-30W) under dynamic condition. Therefore, Ti-W composites exhibit obvious strain strengthening effect. By comparing the applicability of the modified Johnson-Cook (JC) constitutive model and Back-Propagation (BP) neural network model to the mechanical behavior of Ti-W composites, it is found that BP neural network can better describe the quasi-static and dynamic behavior of Ti-W composite.
Key words: Ti-W metal-metal composite; strain rate strengthening; Johnson-Cook (JC) constitutive model; Back-Propagation (BP) neural network model
