预应力对LY12铝层裂强度的影响

Influence of pre-stress on spall strength of LY12 aluminum

通过过盈配合的热装配方法和机械夹紧方法对LY12铝合金平面样品施加了径向预应变,采用平面飞片撞击方法获得了预应力对层裂特性的影响。结果表明:当飞片以500 m/s的速度撞击样品,预应变为0(无预应变)、251×10-6、1108×10-6、1886×10-6时,层裂强度分别为1.130、0.935、0.755、0.643 GPa,初始预应力(变)明显降低了LY12铝层裂强度,证实了材料的层裂强度与初始应力状态密切相关,可为以后的非一维平面应变下的层裂研究提供参考。

A excessively-conjugated heat assembly and a mechanical clamp device were used to achieve the radial pre-strain of disk-shaped LY12 samples. In the experiment, the LY12 samples were impacted by the flyer plates driven by a one-stage light-gas gun, and spall signals of the samples in several pre-strain states were measured by VISAR. The experimental results show that the spall strengths are 1.13, 0. 935, 0. 755 and 0. 643 GPa respectively corresponding to the pre-strains of 0, 251 × 10^-6 , 1 108× 10^-6 and 1 886 × 10^-6 when the samples are impacted by the flyer plates with 500 m/s. The pre-stress （pre-strain） reduces the spall strength of LY12 aluminum obviously. It is confirmed that the spall strength is closely related to the initial stress. It is helpful for the future research on materials spallation in multi-dimensional strain states.