高应变率下铀铌合金的断裂组织特征

The Fracture Morphology and Microstructure of U-Nb Alloy at High Strain Rate

摘要:

对经过内部爆破加载后产生的U-Nb合金破片进行了断口形貌、金相组织等微观分析。结果表明：U-Nb合金在爆炸加载下的断裂方式为剪切断裂；破片组织内部发现因高速应变引起的大量的绝热剪切带，靠近绝热剪切带的基体晶粒发生明显的拉长变形：破片中存在大量的微裂纹，裂纹沿着绝热剪切带扩展，当与沿壳体环向的拉应力形成的纵向主裂纹相交汇时，形成破片。

Abstract:

The fracture morphology and microstructure of Uranium-Niobium caused by explosive loading were investigated. The results show that U-Nb is in shear fracture with explosive loading, there are many adiabatic shear bands(ABS) in microstrcture caused by high strain rate. The grains near the ASB have been elongated obviously. The microcracks exist in fragments and spread along the ASB. The fragments form when the cracks meet with the main cracks resulting from the tensile strain on the circumference direction of U-Nb tubes.