非晶及纳米结构钛合金研究进展

Ti-Based Alloys of Bulk Metallic Glasses and Nanostructure

摘要:

综述了钛基大块非晶的成分-非晶形成能力的对应关系，总结了已知的钛基大块非晶的一次结晶相及力学性能，并阐述了钛基大块非晶的塑性变形机制，以及造成低塑性的因素和改善塑性的方法，着重介绍了铸造纳米结构钛合金的成分、组织和力学性能。通过精巧的成分设计，结合金属模铸造技术，制备出了直径小于5mm，并具有微米尺度β-Ti（M）一次树枝晶相＋纳米尺度棒状β-Ti／γ-TiCu共晶结构的复合组织，其中棒状β-Ti相尺寸在30nm～300nm范围；γ-TiCu共晶基体相由小于10nm的晶粒或亚晶粒组成，这种多层次纳米结构的钛合金具有高强度，同时县有明显的延伸性。

Abstract:

Ti-based bulk metallic glasses (BMGs) developed in the past decade have been reviewed in terms of their compositions, glass-forming abilities and mechanical properties. The cast defects in the BMG samples, which significantly deteriorate the mechanical properties, are discussed and summarized based on the experimental results in the literature. Some results on the cast nanostructured Ti alloys with dendritic ductile beta phase are also reviewed. A special composite microstructure, dendritic beta-Ti(M) (in micrometer size) + rod-like eutectic beta-Ti/gamma-TiCu (in nanometer size), has been obtained in the as-cast cylinders smaller than 5 mm in diameter in the Ti-Cu-Ni-Sn-Ta(Nb) systems. The Ti alloys with such composite microstructure exhibit very high strength and remarkable plasticity.