Mg_(80)Cu_(15)Y_5合金的非晶形成能力及晶化行为

Amorphous-forming Ability and Crystallization Behavior of Mg_(80)Cu_(15)Y_5 Alloy

采用单辊快速凝固法制备出厚约40μm的Mg80Cu15Y5非晶合金薄带,利用XRD、DSC、TEM和HRTEM研究了非晶合金的非晶形成能力和晶化行为,分析了晶化对合金组织结构与性能的影响。结果表明:Mg80Cu15Y5合金的过冷液态温度区间ΔTx和约化玻璃转变温度Trg分别为55 K和0.58,表明其具有较强的非晶形成能力;该合金在退火温度高于473 K后发生明显晶化,从非晶基体中析出Mg2Cu、Cu2Y和Mg晶体相;随着退火温度的升高,合金的硬度呈现出先升高后降低的变化趋势,这与纳米晶体相颗粒的弥散析出、重溶及粗化有关。

Mg80Cu15Y5 amorphous alloy ribbons with the thickness of approximately 40 μm were prepared by single-roll rapid solidification method. The amorphous-forming ability and crystallization behavior were studied using XRD, DSC, TEM and HRTEM. The effects of crystallization on microstructure and mechanical property of the alloy were analyzed. The results show Mg80Cu15Y5 alloy has better amorphous-forming ability, the undercooled liquid region ΔTx is 55 K and the reduced glass-transition temperature Trg is 0.58. The remarkable crystallization of the alloy occurs after annealing above 473 K. Mg2Cu, Cu2Y and Mg crystalline phases are precipitated from the amorphous matrix. With the increase of annealing temperature, the microhardness of the alloy increases first and then decreases. The change in the microhardness of the alloy depends on the precipitation, re-melting and coarsening of the nano-crystalline particles.