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

研究了块体非晶合金Zr55Al10Ni5Cu30在疲劳断裂过程中观察到的裂纹周边的火花发射机制。采用双侧裂纹板试件，在室温空气中进行了该合金的剪切试验。剪切试验的加载速率为15kN/S，用数字图像相关法测量剪切试验试件中裂纹尖端附近的变形。剪切试验表明，试件沿高应变区断裂，并沿断裂路径观察到火花发射。结果还表明，火花发射可能是由配合断口之间的摩擦引起的，尤其是剪切唇区。

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.