Mechanical Properties, Damage and Fracture Mechanisms of Bulk Metallic Glass Materials
Mechanical Properties, Damage and Fracture Mechanisms of Bulk Metallic Glass Materials
复制标题
DOI：
--
复制
发表时间：
2007
影响因子：
10.9
通讯作者：
Z. Zhang;F. Wu;G. He;J. Eckert
中科院分区：
文献类型：
--
作者：
Z. Zhang;F. Wu;G. He;J. Eckert
对Zr、Cu、Ti和Mg基大块非晶合金及其复合材料剪切断裂引起的变形、损伤、断裂、塑性和熔化现象进行了研究和总结。这些非晶合金材料在拉伸和压缩状态下的剪切断裂角往往有明显的差异，并遵循Mohr-Coulomb断裂准则或统一拉伸断裂准则。复合材料的压缩塑性总是高于拉伸塑性，导致显著的不一致性。与整体玻璃相比，含有韧性枝晶的BMG复合材料的增强塑性强烈地依赖于复合材料的微观结构的细节。提出了一种与局部开裂有关的伪塑性变形和损伤机制，用以解释拉压塑性变形的不一致性。此外，在剪切断口上观察到明显的熔化。研究表明，熔融是这些高强度、高弹性能材料中的一种普遍现象，这是BMG及其复合材料在剪切断裂下失效的典型现象。熔化机制可以解释为剪切带中显著的温度升高和材料中储存的大量弹性能量的瞬时释放的组合效应。
The deformation, damage, fracture, plasticity and melting phenomenon induced by shear fracture were investigated and summarized for Zr-, Cu-, Ti- and Mg-based bulk metallic glasses (BMGs) and their composites. The shear fracture angles of these BMG materials often display obvious differences under compression and tension, and follow either the Mohr-Coulomb criterion or the unified tensile fracture criterion. The compressive plasticity of the composites is always higher than the tensile plasticity, leading to a significant inconsistency. The enhanced plasticity of BMG composites containing ductile dendrites compared to monolithic glasses strongly depends on the details of the microstructure of the composites. A deformation and damage mechanism of pseudo-plasticity, related to local cracking, is proposed to explain the inconsistency of plastic deformation under tension and compression. Besides, significant melting on the shear fracture surfaces was observed. It is suggested that melting is a common phenomenon in these materials with high strength and high elastic energy, as it is typical for BMGs and their composites failing under shear fracture. The melting mechanism can be explained by a combined effect of a significant temperature rise in the shear bands and the instantaneous release of the large amount of elastic energy stored in the material.