High-speed Impact Damaging Behavior of Equiaxed New-type α+β dual-phaseTitanium Alloy Plates

Abstract:

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.

Key words:titanium alloy;high-speed impact injury;adiabatic shear bands;protective property