R. Huang, Y. Zheng, S. Luo, H. Bai, P. Wang, Y. Chen, Z. Qu
{"title":"Characterization on Fracture Toughness of Cermet Coating Coupling Instrumented Indentation and X‑Ray Computed Tomography","authors":"R. Huang, Y. Zheng, S. Luo, H. Bai, P. Wang, Y. Chen, Z. Qu","doi":"10.1007/s11340-024-01075-9","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><p>The surface brittle fracture of cermet coating seriously restricts its application. Accurate evaluation of the fracture toughness of cermet coating is a prerequisite for improving its life.</p><h3>Objective</h3><p>This paper aims to propose an accurate characterization method for fracture toughness of cermet coating.</p><h3>Methods</h3><p>By coupling instrumented indentation and X‑ray computed tomography (XCT), the indentation-induced fracture behaviors under various loads within WC-12%Co coatings were studied. The three-dimensional subsurface crack morphologies and the damage evolution within the coating were nondestructively observed by XCT. The indentation response was correlated with the damage evolution. The impact of substrate effects on indentation-induced fracture behaviors was further studied using finite element analysis (FEA).</p><h3>Results</h3><p>The Palmqvist shape of the indentation crack under low loads was successfully identified. The first pop-in event in the load-displacement (<i>P</i>-<i>h</i>) curve was determined to be triggered by bottom cracking, marking the onset of the multiple fracture mode. Laugier’s equation offered a stable and reliable estimation of fracture toughness for the coating in the radial cracking mode.</p><h3>Conclusions</h3><p>XCT plays a crucial role in selecting the appropriate equation for indentation toughness calculation. The critical indentation depth for the first pop-in was suggested as the threshold for reliably extracting intrinsic fracture toughness of cermet coatings. Numerical results revealed a constant linear relationship between the critical depth and coating thickness, and a high sensitivity of the critical depth to yield stress of the substrate. The proposed analytical procedure holds potential for generalization to diverse cermet coatings on metal substrates.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 7","pages":"1037 - 1051"},"PeriodicalIF":2.0000,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Experimental Mechanics","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s11340-024-01075-9","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, CHARACTERIZATION & TESTING","Score":null,"Total":0}
引用次数: 0
Abstract
Background
The surface brittle fracture of cermet coating seriously restricts its application. Accurate evaluation of the fracture toughness of cermet coating is a prerequisite for improving its life.
Objective
This paper aims to propose an accurate characterization method for fracture toughness of cermet coating.
Methods
By coupling instrumented indentation and X‑ray computed tomography (XCT), the indentation-induced fracture behaviors under various loads within WC-12%Co coatings were studied. The three-dimensional subsurface crack morphologies and the damage evolution within the coating were nondestructively observed by XCT. The indentation response was correlated with the damage evolution. The impact of substrate effects on indentation-induced fracture behaviors was further studied using finite element analysis (FEA).
Results
The Palmqvist shape of the indentation crack under low loads was successfully identified. The first pop-in event in the load-displacement (P-h) curve was determined to be triggered by bottom cracking, marking the onset of the multiple fracture mode. Laugier’s equation offered a stable and reliable estimation of fracture toughness for the coating in the radial cracking mode.
Conclusions
XCT plays a crucial role in selecting the appropriate equation for indentation toughness calculation. The critical indentation depth for the first pop-in was suggested as the threshold for reliably extracting intrinsic fracture toughness of cermet coatings. Numerical results revealed a constant linear relationship between the critical depth and coating thickness, and a high sensitivity of the critical depth to yield stress of the substrate. The proposed analytical procedure holds potential for generalization to diverse cermet coatings on metal substrates.
期刊介绍:
Experimental Mechanics is the official journal of the Society for Experimental Mechanics that publishes papers in all areas of experimentation including its theoretical and computational analysis. The journal covers research in design and implementation of novel or improved experiments to characterize materials, structures and systems. Articles extending the frontiers of experimental mechanics at large and small scales are particularly welcome.
Coverage extends from research in solid and fluids mechanics to fields at the intersection of disciplines including physics, chemistry and biology. Development of new devices and technologies for metrology applications in a wide range of industrial sectors (e.g., manufacturing, high-performance materials, aerospace, information technology, medicine, energy and environmental technologies) is also covered.