新型α+β双相钛合金板抗高速冲击损伤行为研究

High-Speed Impact Damaging Behavior of Equiaxed New-Type α+β Dual-Phase Titanium Alloy Plates

采用直径7.5 mm钢丸对新型Ti-Mo-V系α+β双相钛合金板材进行高速冲击试验,使用光学显微镜及扫描电镜,对等轴组织板材抗高速冲击损伤行为进行分析。结果表明:钢丸高速冲击后,损伤部位均未观察到明显的分区现象。冲击着板瞬间,相比于钢丸垂直高速冲击,钢丸冲击方向与板法线方向存在较小偏角时,板材更易发生高速冲击破坏失效,沿板材正面冲击损伤中轴线侧剖后可观察到非对称形态的冲击损伤。冲击损伤部位均形成绝热剪切带,主要分布在正面冲击损伤部位中心及两侧区域,其分布形式主要包括:(1)在冲击损伤中心处呈半弧状分布;(2)在冲击损伤部位两侧沿高速冲击方向约呈45°分布,绝热剪切失效是板材防护失效的主要原因。

A series of high-speed impact tests, with 7.5 mm projectiles, were performed on new-type Ti-Mo-V based α+β dual-phase titanium alloy with equiaxed grains. The penetration damage was analyzed by optical microscope and scanning electron microscope. The results show that there is no obvious zoning phenomenon in the macro crater whether the plates are perforated or not. At the impact point,the change of the projectile penetration angle results in the change of the penetration shape. The protective property of the plates will decrease when the projectile penetrates obliquely, and the asymmetric shape crater can be seen by side-cutting along the central axis of the crater. There are two kinds of adiabatic shear bands which are distributed in the center and two sides of the impact crater:(1) semi-arc distribution in the center of the impact crater;(2) on both sides of the crater center, the distribution is about 45° along the direction of penetration. The maximum shear stress is in the direction of 45 °, and the adiabatic shear band is easy to expand and extend along the direction of the maximum shear stress. The connection and growth of the micro-hole and the micro-crack are the main reason for the failure of the protection.