铸态Ti-20Zr-20Al钛合金动态压缩力学性能与断裂机制研究

采用X射线衍射仪、金相显微镜、分离式霍普金森杆和扫描电镜等手段研究了Ti-20Zr-20Al钛合金在动态压缩条件下的微观结构、力学性能和断裂机制。结果表明,Ti-20Zr-20Al铸态合金由Zr基体相和TiAl/Ti₃Al针状相组成; 随着应变率增加,合金的抗压强度增加,失效应变显著增加; Ti-20Zr-20Al合金的断裂机制为解理断裂; 随着应变率增加,试验压缩断裂后碎片总数增大,平均粒径减小。采用DID模型模拟的材料碎片尺度与实验结果比较吻合,Grady模型与实验结果的偏差较大。

Dynamic Compression Mechanical Properties and Fracture Mechanism of As-cast Ti-20Zr-20Al Titanium Alloy

The microstructure, mechanical properties and fracture mechanism of a Ti-20Zr-20Al titanium alloy under dynamic compression were investigated by means of X-ray diffraction, metallographic microscope, split Hopkinson pressure bar and scanning electron microscope. The results show that Ti-20Zr-20Al alloy consists of Zr matrix phase and TiAl/Ti₃Al acicular colonies phase. With the increase of strain rate, both the compressive strength and the failure strain of the alloy increase and the fracture mechanism of Ti-20Zr-20Al alloy is cleavage fracture. With the increase of strain rate, the total number of fragments after the compression fracture test increases, and the average particle size decreases. The size of the material fragments simulated by using the Dynamic Isolated Decohesion model is more consistent with the experimental results, but there's great deviation between the results of Grady model and experiment.