2519-T87铝合金经速度为816m/s弹丸斜侵后的显微组织演化(英文)

采用显微硬度测试、金相显微镜(OM)、透射电镜(TEM)、电子背散射衍射(EBSD)等手段,研究2519-T87铝合金板材经速度为816m/s的WO-109C型燃烧弹斜侵后弹坑周围的硬度分布和显微组织演化。结果表明:在子弹的侵入阶段,组织中绝热剪切带的数量最多,同时析出相尺寸与原始靶材的相当,显微硬度则较其它阶段的高;在稳定侵彻阶段,绝热剪切带的数量减少,显微带数量增多,同时合金中的析出相粗化,这导致合金显微硬度降低;在子弹离开阶段,组织中存在大量的显微带,析出相细化,显微硬度较稳定侵彻阶段的高。显微硬度的演变是由加工硬化和析出相的粗化所致,而析出相的粗化是由绝热温升所引起的。

Microstructural evolution of 2519-T87 aluminum alloy obliquely impacted by projectile with velocity of 816 m/s

Target made of 2519-T87 aluminum alloy was obliquely impacted by a projectile.Microstructural evolution around the crater was investigated by optical microscopy(OM),transmission electron microscopy(TEM),and electron backscattered diffraction(EBSD).The micro-hardness distribution near the crater after impact was studied.The results indicate that at the entering stage,the amount of adiabatic shear band(ASB) is the most,and the precipitates are as fine as those of the target material;the micro-hardness is higher than that at the other stages.At the stable-running stage,the amount of ASB reduces as the micro-bands increase;the precipitates tend to coarsen,which leads to the decrease of the micro-hardness.At the leaving stage,there is a large amount of micro-bands;the precipitates are refined,and the micro-hardness is higher than that at the stable-running stage.The difference in the micro-hardness of the impact stages is due to work hardening and precipitate coarsening,which is caused by adiabatic temperature rise in the alloy.