Titanium alloys such as Ti-6Al-4V offer a potential lightweight alternative to traditional armour steels for ballistic protection due to their reduced density of approximately 60 % that of steel and tensile properties better than rolled homogenous armour steel. The manufacture of metallic armour often requires substantial thermomechanical processing to meet necessary ballistic performance specifications and thus restricts the complexity of armour designs. Additive manufacturing of Ti-6Al-4V has matured significantly in recent years, achieving outstanding mechanical properties in the as-built condition. In this study, Ti-6Al-4V plates were additively manufactured using both laser powder bed fusion and direct laser metal deposition for ballistic testing. The plates were built in different orientations and subjected to pre-heating or post heat-treatment to investigate the microstructural effect on the ballistic velocity limit (V₅₀). The results show that plates with lamellar microstructure formed through martensite decomposition had higher V₅₀ compared to lamellar microstructure formed via slow cooling through the β-transus. The post heat-treatment increased the V₅₀ due to coarsening of the α-lath and stress relief. It is also apparent that anisotropy of the microstructure, specifically the columnar prior-β grains, affects the ballistic performance. A higher V₅₀ was achieved when the columnar grains were aligned perpendicular to the projectile impact direction.

钛合金如 Ti-6Al-4V 提供了一种潜在的轻质替代传统装甲钢的弹道保护，因为它们的密度降低了钢的约 60%，拉伸性能比轧制均质装甲钢更好。金属装甲的制造通常需要大量的热机械处理以满足必要的弹道性能规范，从而限制了装甲设计的复杂性。近年来，Ti-6Al-4V 的增材制造已显着成熟，在竣工条件下实现了出色的机械性能。在这项研究中，Ti-6Al-4V 板是使用激光粉末床融合和直接激光金属沉积增材制造的，用于弹道测试。₅₀ )。结果表明，与通过β-转变缓慢冷却形成的层状组织相比，通过马氏体分解形成的层状组织具有更高的V ₅₀。由于α-板条粗化和应力消除，后热处理增加了V ₅₀。同样明显的是，微观结构的各向异性，特别是柱状先验β晶粒，会影响弹道性能。当柱状晶粒垂直于弹丸撞击方向排列时，可以获得更高的 V ₅₀。