Investigation of effect of voxel size choice for the measurement and analysis of porous coatings

Christopher Jackson, Ahmed Tawfik, Paul Bills

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


This study aims to investigate the effects of voxel size change with measurement and characterisation of functional characteristics of a porous surface or coating. Prevalent across numerous fields, porous coatings and surfaces have been utilised and exploited for their unique characteristics, particularly in the biomedical field, where their osseointegrative potential is paramount. Due to the topographical nature of this surface type, the use of X-Ray Computed Tomography (XCT) is often dictated when re-entrant features are present. Voxel size is the indicative parameter in determining the resolution of the corresponding scan, with lower values resulting in increased scan times and data size implications but offer an increase in the scale of features that can be obtained. Topographical surface area information and amplitude parameters have been utilised in this comparative study to demonstrate the effects a change of voxel size has on the surfaces extracted from XCT measurements. 

Titanium Alloy (Ti6Al4V) coupon samples (12.7 mm diameter, 4.73 mm avg. thickness) were used for this study. They incorporate a porous plasma sprayed top coating with machining marks present on the opposing surface with a unique engraved identification mark present. A voxel size range of 8 μm to 76 μm was used, these resulted in a topographical surface area decrease, with values of 883 mm2 and 471 mm2 respectively. Amplitude parameters were used on the machining marks only, with root mean square roughness changing from 0.9 μm to 3.1 μm, with large variation between the voxel size intervals. Visible differences are instantly noticeable with the identification mark being only visible at voxel sizes below 25 μm.

Original languageEnglish
Title of host publicationEuropean Society for Precision Engineering and Nanotechnology, Conference Proceedings - 23rd International Conference and Exhibition
Subtitle of host publicationEUSPEN 2023
EditorsO. Riemer, C. Nisbet, D. Phillips
Number of pages4
ISBN (Print)9781998999132
Publication statusPublished - 12 Jun 2023
Event23rd International Conference & Exhibition for European Society for Precision Engineering and Nanotechnology - Technical University of Denmark, Copenhagen, Denmark
Duration: 12 Jun 202316 Jun 2023
Conference number: 23


Conference23rd International Conference & Exhibition for European Society for Precision Engineering and Nanotechnology
Abbreviated titleEUSPEN 2023
Internet address

Cite this