低冲击应力下脆性介质电阻率的实时测量

Measurement of Electrical Resistivity of Brittle Materials under Weak Shock Compression

冲击波压缩下材料宏观性质的变化与微观结构演化有着密切联系。通过改进对称差分电路测量方法,测量K9玻璃在失效破坏过程中的电阻率变化,研究了脆性介质在低冲击波应力下的损伤破坏机制。结果表明,随着冲击波在K9玻璃中传播,K9玻璃的电阻率逐渐下降;在7.6GPa冲击压缩下,K9玻璃由最初的绝缘体状态逐渐转变为电阻率约420Ω.m的稳定状态。

The property variation of brittle material is closely related to its microstructure variation under shock compression.The present work is aimed to understand such a failure process by the measurement of electrical resistivity changes under weak shock compression.After improvements on the Weir＇s differental technique,the electrical resistivity of K9 glass has been measured under shock loading.Experimental results indicate that the electrical conductibility increases as shock wave propagating in the K9 glass.At the shock pressure of 7.6 GPa,the electrical resistivity changes gradually from the insulation state to a constant of about 420 Ω·m.