Microstructure and properties of nacre-like Al2O3-HEOs ceramic prepared by “floe ice” effect in colloidal system

IF 4.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

International Journal of Refractory Metals & Hard Materials Pub Date : 2025-08-29 DOI:10.1016/j.ijrmhm.2025.107409

Yutong Sima , Cheng Chen , Zhenhua Long , Xingwei Xu , Taijun He , Dong Yang , Yi Han , Ji Xiong , Junbo Liu

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Abstract

Compared to conventional ceramics, the hardness, strength, and toughness of textured alumina ceramics with a brick-mortar structure are significantly enhanced. In this study, a simple method was employed to fabricate alumina ceramics with improved fracture toughness by combining alumina platelets with high entropy oxides (HEOs) composed of MgO-Al₂O₃-ZrO₂-TiO₂-SiO₂ by “floe ice” effect in colloidal system, forming a brick-mortar structure. Microstructure, Vickers hardness, relative density, fracture strength, and wear resistance, were thoroughly examined. The results indicated that the relative density of the composite alumina ceramics was 96.5 %, with a Vickers hardness of 1916 ± 50 HV₁, a fracture strength exceeding 310 MPa, and a fracture toughness of 5.167 ± 0.15 MPa·m^1/2. These properties represented a 2.3-fold increase in fracture toughness compared to conventional alumina ceramics (2.217 ± 0.34 MPa·m^1/2). The improved fracture toughness is attributed to the excellent wettability and versatility of HEO as an intergranular liquid phase, coupled with the effective crack deflection facilitated by the brick-mortar structure formed by the Al₂O₃ platelets. This method is simple and cost-effective, which offers a promising approach for the fabrication of high-toughness alumina ceramics with complex geometries.

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胶体体系中“浮冰”效应制备纳米Al2O3-HEOs陶瓷的微观结构与性能

与传统陶瓷相比，具有砖-砂浆结构的织构氧化铝陶瓷的硬度、强度和韧性都得到了显著提高。在这项研究中，采用一种简单的方法，将氧化铝薄片与由MgO-Al₂O₃-ZrO₂-TiO₂-SiO₂组成的高熵氧化物（HEOs）在胶体体系中通过“浮冰”效应结合，形成砖-砂浆结构，制备了具有提高断裂韧性的氧化铝陶瓷。对显微组织、维氏硬度、相对密度、断裂强度和耐磨性进行了全面检查。结果表明，复合氧化铝陶瓷的相对密度为96.5%，维氏硬度为1916±50 HV1，断裂强度超过310 MPa，断裂韧性为5.167±0.15 MPa·m1/2。这些性能表明，与传统氧化铝陶瓷（2.217±0.34 MPa·m1/2）相比，断裂韧性提高了2.3倍。断裂韧性的提高是由于HEO作为晶间液相具有优异的润湿性和通用性，再加上Al₂O₃薄片形成的砖-砂浆结构促进了裂缝的有效挠曲。该方法简单、经济，为复杂几何形状的高韧性氧化铝陶瓷的制备提供了一种很有前途的方法。

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来源期刊

$International Journal of Refractory Metals & Hard Materials$

International Journal of Refractory Metals & Hard Materials 工程技术-材料科学：综合

CiteScore

7.00

自引率

13.90%

发文量

236

审稿时长

35 days

期刊介绍： The International Journal of Refractory Metals and Hard Materials (IJRMHM) publishes original research articles concerned with all aspects of refractory metals and hard materials. Refractory metals are defined as metals with melting points higher than 1800 °C. These are tungsten, molybdenum, chromium, tantalum, niobium, hafnium, and rhenium, as well as many compounds and alloys based thereupon. Hard materials that are included in the scope of this journal are defined as materials with hardness values higher than 1000 kg/mm2, primarily intended for applications as manufacturing tools or wear resistant components in mechanical systems. Thus they encompass carbides, nitrides and borides of metals, and related compounds. A special focus of this journal is put on the family of hardmetals, which is also known as cemented tungsten carbide, and cermets which are based on titanium carbide and carbonitrides with or without a metal binder. Ceramics and superhard materials including diamond and cubic boron nitride may also be accepted provided the subject material is presented as hard materials as defined above.