激光表面处理对工业级锆基块体非晶合金弯曲变形和缺口韧性的影响

目的 改善块体非晶合金的弯曲力学性能，同时考虑航空结构材料选材的经济性，研究激光表面处理工艺对工业级Zr_49.7Ti₂Cu_37.8Al₁₀Er_0.5块体非晶合金弯曲变形和缺口韧性的影响规律。方法 采用低纯原料和低真空制备条件获得工业级Zr_49.7Ti₂Cu_37.8Al₁₀Er_0.5块体非晶合金试样，考虑到弯曲条件下试样受到拉伸和压缩2种正应力状态，研究不同处理工艺和激光处理表面对试样弯曲变形和缺口韧性的影响。结果 当激光处理表面位于弯曲试样的2个侧表面时，其对试样的塑性变形能力和断裂强度没有明显的影响，但会显著降低试样的缺口韧性，从(56.4±3.4)MPa·m^1/2降低到(26.2±4.8)MPa·m^1/2；激光处理表面位于弯曲试样的受拉侧时，试样的弯曲断裂强度从2 150 MPa降低到1 800 MPa；当激光处理表面位于...

Effect of Laser Surface Treatment on Bending Deformation and Notch Toughness of Industrial-grade Zr-based Bulk Metallic Glasses

Considering that the positive effect of laser surface treatment (LSM) on the plasticity of bulk metallic glasses (BMGs) and the economy of selection on aeronautical materials, the work aims to study the effect of LSMs on the bending deformation and toughness of industrial-grade Zr49.7Ti2Cu37.8Al10Er0.5 BMGs. Industrial-grade Zr49.7Ti2Cu37.8Al10Er0.5 BMGs were obtained through low purity raw materials and low vacuum preparation conditions. Considering that the specimens were subjected to both tensile and compressive normal stress states under the bending condition, the effects of different treatment processes and different laser treated surfaces on the bending deformation and toughness of the specimens were studied. When the laser-treated surfaces were located on the two lateral surfaces of the bending specimen, it had no significant effect on the plastic deformation and fracture strength of the specimen, but it significantly reduced the notch toughness of the specimen from (56.4±3.4) MPa.m1/2 to (26.2±4.8) MPa.m1/2. When the laser-treated surface was located on the tensile side of the bending specimen, the bending fracture strength of the specimen decreased from 2 150 MPa to 1 800 MPa. When the laser-treated surface was located on the compressive side of the bending specimen, the bending fracture strength of the specimen increased from 2 150 MPa to 2 550 MPa, but there was no significant effect on its notch toughness. The effects of the compositional changes and residual stress induced by LSM for the industrial-grade Zr49.7Ti2Cu37.8Al10Er0.5 BMGs on the bending mechanical behavior and notch toughness are closely related to the stress state. The positive coupling of the residual stress and the external loading stress can amplify the effect of external loading stresses. Meanwhile, the compositional differences between the surface and the central part may appear as stress concentration points, thus leading to the formation of crack sources and reducing the fracture strength of the specimen.