Ultra-high frequency treatment: Toughening PEO coating of Zr alloys by dispersed small pores

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International Pub Date : 2025-06-01 DOI:10.1016/j.ceramint.2025.02.144

Lei Liu , Shuai Dong , Xiao-Bo Chen , Fulin Wang , Fenghua Wang , Jie Dong

{"title":"Ultra-high frequency treatment: Toughening PEO coating of Zr alloys by dispersed small pores","authors":"Lei Liu , Shuai Dong , Xiao-Bo Chen , Fulin Wang , Fenghua Wang , Jie Dong","doi":"10.1016/j.ceramint.2025.02.144","DOIUrl":null,"url":null,"abstract":"<div><div>Plasma electrolytic oxidation (PEO) ceramic coatings are known to exhibit porosity and brittleness, while the regulation of pores into more dispersed and smaller structures is a proven method for enhancing the toughness of ceramics. In this work, ultra-high frequency (≥10 kHz) pulse current was applied to modify the discharge pores in the PEO coating of Zr alloys. Cross-sectional morphology reveals that large pores in the outer layer of the coating at 10 kHz exhibited a diameter of about 10 μm, showing a remarkable reduction in comparison to that at 0.1 (40 μm) and 1 kHz (25 μm). Particularly, a porous sublayer was identified in this coating, with pore diameters measuring less than 1–2 μm and a thickness approximately half that of the outer layer. It was proposed that, with the increase of frequency, the refined pores and increased pore number are respectively attributed to the reduced pulse on time and increased number of pulse discharges. Vickers indentation tests indicate that the coatings at 0.1 and 1 kHz occurred distinct fracturing under a load of 49 N, whereas no notable fracture was observed in the coating at 10 kHz under 196 N load. This suggests that the dispersed small pores at ultra-high frequency can inhibit the initiation and propagation of cracks effectively, thereby enhancing the toughness of the PEO coating significantly. This work offers a critical insight into the toughening of PEO coatings.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 15","pages":"Pages 19761-19779"},"PeriodicalIF":5.1000,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ceramics International","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0272884225008090","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}

引用次数: 0

Abstract

Plasma electrolytic oxidation (PEO) ceramic coatings are known to exhibit porosity and brittleness, while the regulation of pores into more dispersed and smaller structures is a proven method for enhancing the toughness of ceramics. In this work, ultra-high frequency (≥10 kHz) pulse current was applied to modify the discharge pores in the PEO coating of Zr alloys. Cross-sectional morphology reveals that large pores in the outer layer of the coating at 10 kHz exhibited a diameter of about 10 μm, showing a remarkable reduction in comparison to that at 0.1 (40 μm) and 1 kHz (25 μm). Particularly, a porous sublayer was identified in this coating, with pore diameters measuring less than 1–2 μm and a thickness approximately half that of the outer layer. It was proposed that, with the increase of frequency, the refined pores and increased pore number are respectively attributed to the reduced pulse on time and increased number of pulse discharges. Vickers indentation tests indicate that the coatings at 0.1 and 1 kHz occurred distinct fracturing under a load of 49 N, whereas no notable fracture was observed in the coating at 10 kHz under 196 N load. This suggests that the dispersed small pores at ultra-high frequency can inhibit the initiation and propagation of cracks effectively, thereby enhancing the toughness of the PEO coating significantly. This work offers a critical insight into the toughening of PEO coatings.

查看原文本刊更多论文

超高频处理：通过分散的小孔隙使Zr合金的PEO涂层增韧

众所周知，等离子体电解氧化（PEO）陶瓷涂层具有多孔性和脆性，而将孔隙调节成更分散、更小的结构是提高陶瓷韧性的一种行之有效的方法。采用超高频（≥10 kHz）脉冲电流对Zr合金PEO涂层中的放电孔进行了修饰。横截面形貌分析表明，在10 kHz时，涂层外层的大孔直径约为10 μm，与0.1 （40 μm）和1 kHz （25 μm）时相比，孔径明显减小。特别是，在该涂层中发现了多孔亚层，孔径小于1-2 μm，厚度约为外层的一半。随着脉冲频率的增加，孔隙的细化和孔隙数的增加分别归因于脉冲时间的减少和脉冲放电次数的增加。维氏压痕试验表明，在49 N的载荷下，涂层在0.1和1 kHz时发生明显的断裂，而在196 N的载荷下，涂层在10 kHz时没有发生明显的断裂。这说明超高频分散的小孔隙可以有效地抑制裂纹的萌生和扩展，从而显著提高PEO涂层的韧性。这项工作为PEO涂层的增韧提供了重要的见解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Ceramics International 工程技术-材料科学：硅酸盐

CiteScore

9.40

自引率

15.40%

发文量

4558

审稿时长

25 days

期刊介绍： Ceramics International covers the science of advanced ceramic materials. The journal encourages contributions that demonstrate how an understanding of the basic chemical and physical phenomena may direct materials design and stimulate ideas for new or improved processing techniques, in order to obtain materials with desired structural features and properties. Ceramics International covers oxide and non-oxide ceramics, functional glasses, glass ceramics, amorphous inorganic non-metallic materials (and their combinations with metal and organic materials), in the form of particulates, dense or porous bodies, thin/thick films and laminated, graded and composite structures. Process related topics such as ceramic-ceramic joints or joining ceramics with dissimilar materials, as well as surface finishing and conditioning are also covered. Besides traditional processing techniques, manufacturing routes of interest include innovative procedures benefiting from externally applied stresses, electromagnetic fields and energetic beams, as well as top-down and self-assembly nanotechnology approaches. In addition, the journal welcomes submissions on bio-inspired and bio-enabled materials designs, experimentally validated multi scale modelling and simulation for materials design, and the use of the most advanced chemical and physical characterization techniques of structure, properties and behaviour. Technologically relevant low-dimensional systems are a particular focus of Ceramics International. These include 0, 1 and 2-D nanomaterials (also covering CNTs, graphene and related materials, and diamond-like carbons), their nanocomposites, as well as nano-hybrids and hierarchical multifunctional nanostructures that might integrate molecular, biological and electronic components.