微观组织对Ti6321钛合金靶板爆炸断裂失效的影响

Effect of Microstructure on Explosion Failure of Ti6321 Titanium Alloy Target Plate

通过不同热处理工艺获得不同组织的Ti6321钛合金靶板,研究微观组织对Ti6321钛合金靶板在爆炸加载过程中变形和断裂行为的影响。结合光学显微镜和扫描电子显微镜,对爆炸回收后的靶板进行微观断口和失效分析。结果表明:等轴组织靶板具有较高的抗变形能力,魏氏组织靶板具有较高的抗层裂破坏能力和较低的厚度减薄率,断裂模式包括塑性变形及中心颈缩环、沿颈缩环部分断裂、沿颈缩环全部断裂和中心完全撕裂;在200 g TNT爆炸加载下,双态组织靶板发生拉伸和剪切断裂;在300 g TNT爆炸加载下,等轴组织靶板发生拉伸、剪切断裂和层裂,双态组织靶板发生剪切断裂和层裂,断口均为韧性断裂;魏氏组织靶板在两种TNT药量加载下均产生剪切断裂,断口为韧性和脆性的混合型断裂,靶板的层裂和剪切断裂均为绝热剪切失效。

Ti6321 titanium alloy target plates with different microstructures were obtained through different heat treatments.The effect of microstructure on the deformation and fracture behavior of Ti6321 titanium alloy target plate during explosive loading was studied.The fracture and micro-failure analysis of target plate after explosion were carried out by using optical microscope and scanning electron microscope.The results show that the equiaxed target plate has a higher resistance to deformation,the Widmanstätten target plate has a higher resistance to spallation failure and a lower thickness reduction rate.The fracture modes include plastic deformation and central necking ring,partial break along the necking ring,complete break along the necking ring and complete tear in the center.The tensile and shear fracture occur in the bimodal target plate under the explosive loading of 200 g TNT.Under the explosive loading of 300 g TNT,the tensile,shear fracture and spallation occur in the equiaxed target plate,and the shear fracture and spallation occur in the bimodal target plate,the fractures of which are both ductile fracture.Only shear fracture occurs in the Widmanstätten target plate under the explosive loading of both TNTs,and the fracture is a mixed ductile and brittle fracture.The spallation and shear fracture of target plates are adiabatic shear failure.