Porosity is present in many materials. Whether it is a defect or a feature, its quantification is critical. For example, understanding the various types of porosity defects can inform adjustments in the manufacturing process in order to improve the material's properties. In a material that is porous by design, the expected level of porosity can be adapted through conception changes. Imaging techniques such as microCT, FIB-SEM, SEM, and TEM allow for analysis of porous materials to quantify micro pores, sponge-type voids, large macro-voids, inclusions, and so forth.
Thermo Scientific Avizo Software is an all-in-one image analysis platform that allows for the visualization, processing, and quantification of porous materials. Avizo Software enables the detection and classification of various types of porosity (for example, connected vs isolated; macro pores vs micro pores), even on images with complex artifacts (for example, pore back effect in FIB-SEM). Many porosity properties and statistics can be calculated, such as volume fraction, largest ball fitting through a given pore, pore size distribution, pore throat size distribution, pore orientation, shape factor, and more. Porosity can be turned into a model (Pore Network Model), allowing for rapid understanding and exploration of the pore space, featuring spheres or ellipsoids and sticks type visualization with property mapping. Avizo Software also allows the direct calculation of the absolute permeability of the material from the segmented pore space.
Fibers are used in concrete to increase its structural integrity, enhancing toughness, flexural strength, and resistance to shrinkage-induced cracking. However, the inclusion of fiber influences the concrete's porosity and permeability, which directly impacts its durability.
In this example, the porosity and permeability of a fiber reinforced concrete is analyzed. The concrete pore space is identified, and the connected vs isolated porosity is classified. The isolated porosity is represented as a pore network model, and the permeability of the concrete is evaluated. The streamlines representing the velocity field in the permeability experiment simulation are visualized passing through the sample. The fibers are also identified thanks to a dedicated algorithm for fiber segmentation.
For bone TE applications, the selection of the scaffold is a crucial parameter. According to the bone structure, a highly porous, open-pored, and fully interconnected geometry is desired.
In this study, four different ceramic biomaterials (Sponceram , Osseolive, Cerasorb, and 45S5-Bioglass) have been systematically analyzed and evaluated as regards their applicability for bone Tissue Engineering.
Read the article
In situ draining experiments were carried out in order to understand the nature of the residual static liquid holdup in SiC foams. The goal of these experiments is to enable better future modeling and design of structured reactors that are based on SiC foams.
Read the article co-written with university of Manchester, SICAT
Solid Oxide Fuel Cells (SOFCs) are one of the most promising electrochemical devices for the efficient co-generation of heat and electricity of fuel gases. Advantages of this type of fuel cell include fuel flexibility, low emissions, and stability. The electrochemical performance is closely related to the microstructure of the electrodes, where the chemical reaction and mass transport take place.
This video demonstrates the concept of multi-length scale imaging and simulation of a novel-structured tubular SOFC anode to obtain effective mass transport. Microstructure parameters such as tortuosity and permeability are measured from the porous phase of the electrode extraction and are then used for the material definition of the solid region in the full-thickness anode simulation. Thus, the characteristic tortuosity, permeability, and effective transport parameter can be estimated and further used in the electrochemical performance simulation.
Bubbles in food create an aerated structure that enhances the product appearance and properties (smoothness, creaminess, crispness, etc.). Avizo Software provides efficient methods of segmenting the bubbles and quantifying both their attributes and size distribution.
Avizo Software's Pore Network Modeling allows the creation of an equivalent network model of the porous distribution for advanced analysis of the bubbles' interconnections and properties.
Nanoporous gold is a high-interest material in the field of catalytic and sensor applications. It can be imagined as a porous metal sponge with pore sizes in the range of a few tens of a nanometer (one thousand times smaller than the diameter of a human hair).
Image stack acquired with Helios 600 FIBSEM, Slice&View G2 and visualized with Avizo Software - all by Dr. K. Thiel, Fraunhofer IFAM.
Sample courtesy of K.R. Mangipudi, Institute for Materials Physics, University of Goettingen. Voxel size: 10x13x10nm, whole analysed volume size: ca. 6x2x1.3 µm.
Avizo Software provides dedicated tools for porosity analysis: