高性能软磁高熵非晶合金的探索和性能研究

High-entropy amorphous alloys (HE-AAs) are multi-component (above 4), multi-principal-element, equiatomic or near-equiatomic, novel alloy materials with high configuration entropy and mixing entropy. HE-AAs are metastable materials which are fabricated through incorporating structural and chemical disorder into alloys. HE-AAs possess unique high-entropy effects, glass forming ability (GFA) and excellent properties, which provides a new viewpoint to develop high-performance amorphous alloys. However, scientific issues including the driving force for vitrification, thermodynamic properties and structure-property correlations, need to be eagerly addressed. The present project will aim at incorporating high mixing entropy into soft-magnetic Fe-based amorphous alloys through composite substitution and micro-alloying, and exploring excellent soft-magnetic HE-AAs with high GFA. Through further combination with suitable treatment processes, we will realize effective modulation on the GFA, magnetic and mechanical properties of HE-AAs. We will perform the thermodynamically quantitative characterization on HE-AAs. Combining the main factors influencing the vitrification behaviors with high mixing entropy characteristics, we will propose an effective thermodynamic criterion model. In this project, we may obtain creative research achievements including criteria for compositional modulation, thermodynamically quantitative characterization, and exploration of high-performance soft-magnetic amorphous alloys. We will further explore 1-2 new amorphous alloy systems, which will provide theoretical support for key techniques of practical applications of amorphous alloys.

高熵非晶合金是多组元（四组元以上）、多主元、各组元等原子比或近等原子比、具有高构型熵和混合熵的新型合金材料。高熵非晶合金是通过在体系中引入结构无序和化学无序而合成的亚稳材料，其独特的高熵效应和非晶形成属性，以及优异性能为开发高性能非晶合金提供一个新视角，但其非晶化驱动力、热力学性质及结构-性能的相关性等科学问题亟待澄清。本项目拟在软磁Fe基非晶合金中，通过复合替代和微合金化，引入高混合熵，探索具有高玻璃形成能力和优异软磁性能的高熵非晶合金。并结合适当处理工艺实现对其玻璃形成能力、磁性和力学等性能的有效调控。对高熵非晶合金进行热力学定量表征，把影响非晶化行为的主要因素与高混合熵特征相融合，提出有效的热力学判据模型。本项目有望在成分调控准则，热力学定量表征和高性能软磁非晶合金探索三个方面获得创新性研究成果。开发1-2种新非晶合金体系，并为其实践应用的关键技术提供理论支持。

非晶合金和基于高的混合熵和结构熵理念而获得的高熵合金具有比传统晶态软磁材料更优良的磁性能。目前，软磁高熵合金/非晶合金的开发与应用是研究热点。此外高熵合金具有优异的力学性能，在高性能涂层和金属基复合材料的应用也备受关注。.本项目设计了三种成分体系的磁性合金：机械合金化法制备的FeSiBAlNiM(M= C,Nb,Cu,Ag,Cox,Ce,Gd)高熵非晶合金粉末，单辊旋淬法制备的FeCoBM(M=Nb,Mo,Ta,Zr, NbNi)金属玻璃薄带和电弧熔炼法制备的FeCoBTaM(M=Mo,Zr)高熵合金。通过成分设计和不同工艺处理（退火和低温处理）调制相组成和微观结构，提升软磁性能，并同时改善合金的耐蚀性。. 机械合金化FeSiBAlNiM(M=C,Ag)的球磨产物为非晶和纳米晶共存的复合材料。中等原子Co、大原子Ce和Gd的添加都明显缩短了非晶相的形成时间，提高了玻璃形成能力(GFA)。发现第六组元与基体元素的原子尺寸差别越大，形成高熵非晶合金的GFA越高。ΔHmix数值较正时，促进机械合金化粉末获得固溶体。C和Ce添加还显著改善了基体高熵合金粉末的热稳定性。C添加诱导高熵合金粉末由半硬磁性向软磁性转变。适当的退火和低温处理，都能大幅度提升高熵合金/非晶合金的软磁性能。在-20℃保温12h的软磁(Fe0.7Co0.3)75B21Ta4非晶合金薄带的饱和磁化强度达到140emu/g, 远高于淬态薄带（73.8emu/g），钝化区宽度远宽于淬态，表明具有优异的海水耐点蚀性。Zr添加有损于FeCoBTa合金软磁性的改善。低温处理的FeCoBTaMo高熵合金具有最大的Ms数值，说明具有最优的软磁性能。. 此外扩充工作研究发现，通过热压烧结法在Q235钢上制备了高质量CoCrFeNi(Cu,W,W0.5Mo0.5,Mo)涂层，CoCrFeNiW涂层具有高的显微硬度及优异的耐磨性。这与较高含量的金属化合物及大小均匀、形貌规则的析出相有关。利用SPS制备了CuZrAlTiNiW/Al基复合材料。含有30vol.%增强体复合材料具有高的硬度值，高达661HV。含有20vol.%增强体的复合材料具有高的断裂强度(544MPa)。增强体在基体上以核壳结构的形式存在，有助于复合材料综合力学性能的提升。此外复合材料在海水溶液中具有较宽的钝化区，耐点蚀性好。