Study on the Mechanism of Spark Emissions Observed in Fatigue of Zr-based Bulk Amorphous Alloy in Air

本文研究了非晶合金Zr55Al10Ni5Cu30疲劳断裂过程中裂纹外围火花发射的机理。采用双面裂纹板试样在室温空气中进行了合金的剪切试验。剪切试验加载速率为15kN/s。采用数字图像相关（DIC）方法测量剪切试件裂纹尖端周围的变形。剪切试验表明，试样沿高应变区断裂，沿高应变区有火花释放。结果还表明，火花排放可能是由配合断口之间的摩擦引起的，特别是剪切唇区。

The present study investigates the mechanism of spark emissions from crack peripheries observed during the fatigue fracture process of a bulk amorphous alloy Zr55Al10Ni5Cu30. Shear tests of the alloy were performed by using the double-edge-cracked plate specimens at room temperature in air. The loading rate of the shear tests was 15kN/s. The digital image correlation (DIC) method was used to measure deformation around the crack tips in the shear test specimens. The shear tests showed that specimens were fractured along highly strained areas and spark emissions were observed along such fracture paths. The results alsorevealed that spark emissions may have been induced by friction between mating fracture surfaces, especially shear lip regions.