高强高韧Mg60Cu16Ni10Nd14块体非晶合金的研究

Study on Mg60Cu16Ni10Nd14 Bulk Amorphous Alloy with High Strength and Good Plasticity

摘要:

采用铜模铸造法制备了直径为5 mm的Mg60Cu16Ni10Nd14块体非晶合金，利用扫描电镜（SEM）、透射电镜（TEM）X射线衍射 (XRD)和差示扫描量热仪 (DSC)研究了其组织、相结构和热稳定性。结果表明：合金为完全的非晶结构，且出现了相分离；玻璃转变温度Tg、晶化温度Tx分别为431和488 K，过冷液相区?Tx为57 K，表明该合金具有较大的玻璃形成能力。压缩试验表明：合金的压缩断裂强度为653 MPa，断口出现的大量韧窝是合金塑性变形量达到2.5%的主要原因。

Abstract:

Mg60Cu16Ni10Nd14 bulk amorphous alloy with a diameter of 5 mm was prepared by copper mould casting. Its microstructure, phase structure and thermal stability were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The results show that the alloy is completely composed of amorphous phase, and phase-separated regions are homogeneously distributed in the as-cast sample. The glass transition temperature Tg and the crystallization temperature Tx of the alloy are 431 and 488 K, respectively, and the temperature interval of the supercooled liquid region ?Tx is 57 K, which means the quaternary amorphous alloy has great glass forming ability. The compressive test shows that the fracture strength of 653 MPa and the plastic elongation of 2.5% are obtained. The good plasticity is because of lots of dimples on fracture surface.