多相V-Ti-Ni氢分离合金脉冲电流辅助异步轧制成形工艺及其机理研究

Multiphase V-Ti-Ni alloys containing V-rich phase and eutectic Ni-Ti compounds, can achieve a good balance between hydrogen permeability and hydrogen embrittlement resistance. Therefore, it has a broad application prospect in the field of hydrogen membrane separation. Aim at the problems of high deformation resistance, easily oxidized, and poor formability at low temperature, the pulse current and different speed rolling are applied to the forming of multi-phase V-Ti-Ni alloys in the project, to improve the forming performance and efficiency of the alloys, and reduce the manufacturing cost of the alloy membranes. By studying the microstructure evolution of multiphase V-Ti-Ni alloys during different speed roll forming process by the pulse current, and the influence of the microstructure evolution on roll formability, mechanical properties and hydrogen permeability of the alloys, electroplastic-different speed roll forming mechanism of multi-phase V-Ti-Ni alloys is revealed, and the theoretical model of the relationship of pulsed current parameters, rotation speed ratio, microstructure, roll formability, mechanical properties is established. Based on this model, the process and the parameters of the technology of pulse current auxiliary different speed roll forming for multiphase V-Ti-Ni alloys, and ultimately the forming with high efficiency, energy saving, low-cost of multiphase V-Ti-Ni alloy membranes for hydrogen separation is achieved, increasing hydrogen flux of the alloy membranes. Through the research of this project, a foundation of different speed roll forming by the pulse current for the hydrogen separation alloy membranes is laid.

包含富V相和共晶Ni-Ti化合物的多相 V-Ti-Ni合金，能够在氢渗透率与氢脆抗力之间达到很好平衡，因此，在氢气膜分离领域具有广阔的应用前景。针对多相 V-Ti-Ni合金的变形抗力大、易氧化、低温成形困难，本项目提出将脉冲电流和异步轧制应用于多相 V-Ti-Ni合金成形上，提高其成形性能与效率，降低合金膜制造成本。通过研究脉冲电流辅助下合金异步轧制过程中的显微组织演变规律，以及其对轧制成形性能、力学性能及氢渗透率影响，揭示合金电致塑性异步轧制成形机理，建立脉冲电流参数、异速比、显微组织、轧制性能及力学性能间相关性的理论模型；基于此模型制定多相 V-Ti-Ni合金脉冲电流辅助异步轧制成形的工艺流程，优化工艺参数，最终实现多相 V-Ti-Ni氢分离合金膜的高效节能、低成本的制造成形，提高合金膜的氢渗透通量。本项目研究成果将为脉冲电流辅助异步轧制工艺应用于氢分离合金膜成形奠定基础。

随着氢燃料电池、冶金和半导体等领域的快速发展，对高纯氢气的需求日益剧增。利用合金膜分离氢气是高纯氢气提纯的重要方法。目前工业用于提纯高纯氢的Pd-Ag合金膜成本非常高。包含富V相和Ni-Ti化合物的多相 V-Ti-Ni合金，能够在氢渗透率与抗氢脆性之间达到很好平衡，且价格相对较低，在氢气膜分离领域具有广阔的应用前景。针对多相 V-Ti-Ni合金的变形抗力大、易氧化、低温成形困难，本项目旨在优化合金成分及提高合金膜低温成形性能与效率，降低合金膜制造成本。本项目采用了金属凝固学理论、塑性变形理论、电致塑性理论、脉冲电流辅助轧制和异步轧制实验研究、多尺度显微组织分析方法(OM、SEM、XRD、TEM、EBSD等)、力学性能和氢渗透性能测试等全方面的研究技术手段，获得了多相V-Ti-Ni氢分离合金成分对合金显微组织、力学性能和氢渗透性能影响规律，优化出了高的氢渗透性能、抗氢脆性能和机械性能的多相V60Ti20Ni20合金膜。构建了脉冲电流辅助轧制设备，在此基础上，分析了多相V60Ti20Ni20合金膜脉冲电流辅助和异步轧制成形的变形机理及显微组织结构演变规律，优化了合金热处理工艺参数以及低温轧制成形工艺参数，提出了高效、低成本制备成形高强、超薄、高性能的多相V-Ti-Ni氢分离合金膜的有效路径。本项目已发表相关论文10篇，其中SCI论文9篇，EI论文1篇。培养研究生3名。本项目的研究成果补充了多相V-Ti-Ni合金膜的显微组织与力学性能、成形性能和氢渗透性能的相关知识，完善了非钯基氢分离合金膜的知识体系，并能够为高强、超薄、高性能的多相V基合金膜大规模制造成形提供理论基础。