Y含量对Zr47–xCu46Al7Yx合金非晶形成能力及力学性能的影响

Effect of Yttrium Content on the Glass-forming Ability and Mechanical Properties of Zr47–xCu46Al7Yx Bulk Metallic Glasses

摘要:

采用高真空电弧熔炼喷射成形法制备Zr47–xCu46Al7Yx(x=3~8)大块非晶合金。采用X射线衍射分析、差示扫描量热仪、扫描电子显微镜、压缩试验和硬度试验分别研究Y含量对合金的非晶形成能力、显微组织、断口形貌及力学性能的影响。研究结果表明：Y含量对合金系的非晶形成能力和力学性能有显著影响，(4~7)at%Y含量试样由完全非晶组织构成，其过冷液相区ΔTx为56~71K，约化玻璃转变温度Trg为0.665~0.678，但在3与8at%Y含量试样非晶基体中出现了极少量结晶组织。大块非晶具有较好力学性能，其抗压强度为1803~1899MPa，维氏硬度为5.22~5.39GPa，且具有较强非晶形成能力的试样相应地具有较好的力学性能。大块非晶在压缩中以纯弹性变形方式发生脆性断裂，断口光滑平整，为典型脉络状花纹。

Abstract:

Zr47–xCu46Al7Yx(x=3~8) bulk metallic glasses (BMGs) were prepared by injection in copper mould with arc melting. The effect of Y content on the glass-forming ability (GFA), microstructures, fractured surfaces and mechanical properties of the alloys were investigated by using X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM), compression tests and hardness tests, respectively. Results show: Y content has evident effect on the GFA and mechanical properties, the BMGs with 4~7at%Y contents only contain amorphous phases and possess a larger supercooled liquid region ΔTx with value of 56~71K and a better reduced glass transition temperature Trg with value of 0.665~0.678, but very few crystalline phases appear on the BMGs with 3 and 8at%Y contents. The BMGs possess better mechanical properties with compression strength of 1803-1899MPa and Vickers hardness of 5.22~5.39GPa, the BMGs with the better GFA correspondingly possess the better mechanical properties. In compression test, the BMGs happen brittle fracture by pure elastic deformation way, and all fractured surfaced are flat and smooth with typical vein-like morphologies.