Direct monitoring of porosity evolution by dynamic modulus measurements: Three case studies

Abstract

Porous materials are playing an increasingly relevant role in several fields and industrial sectors with structural and functional applications. Their properties critically depend on the relative density and pore morphology thus it is of great importance monitoring the variations of such structural features. Among the experimental techniques commonly used for investigating the microstructure evolution of porous materials, Mechanical Spectroscopy (MS) provides damping and dynamic modulus of the material during heat treatments. In this work three cases of possible pore structure evolution in different metallic alloys have been examined by MS: (i) growth and coalescence of pores, (ii) closure of pores of nanometric size and (iii) no change of porosity.

The results show how dynamic modulus measurements can be successfully employed for a direct monitoring of porosity variations during heating. The technique is quite sensitive and allows to identify the temperature range where pore evolution takes place providing information useful to orientate heat treatments of porous materials.

Keywords:

• Porous metals
• mechanical spectroscopy
• dynamic modulus

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Marcello Cabibbo

Marcello Cabibbo Full Professor of Metallurgy at Polytechnic University of Marche. The main research topics are: (i) high temperature mechanical behavior of light alloys and steels, (ii) characteristics of thin coatings, and (iii) microstructural characterization of light alloys, steels, cast iron, superalloys and Cu alloys.

Chiara de Crescenzo

Chiara de Crescenzo Post-doc at the University of Rome Tor Vergata. The main research topics are: (i) 3D additive manufactured lattice structures, (ii) evaluation and prediction of surface roughness in additive manufactured parts, and (iii) nickel alloys welding and repairing by high density energy processes.

Roberto Montanari

Roberto Montanari Full Professor of Metallurgy at the University of Rome Tor Vergata. The main research topics are: (i) structure and micro-chemistry of liquid metals, (ii) structural and plasma facing materials for nuclear fusion reactors, (iii) biodegradable alloys for medical applications, and (iv) microstructure and properties of 3D printed alloys.

Maria Richetta

Maria Richetta Associate Professor of Design and Methods of Industrial Engineering. The main research topics are: (i) lattice structures and topological optimization, (ii) plasma facing materials for nuclear fusion reactors, (iii) structure and characteristics of LDH coatings for medical applications, and (iv) microstructure and properties of 3D printed alloys.

Alessandra Varone

Alessandra Varone Associate Professor of Metallurgy at the University of Rome Tor Vergata. The main research topics are: (i) structure and micro-chemistry of liquid metals, (ii) structural and plasma facing materials for nuclear fusion reactors, (iii) biodegradable alloys for medical applications, and (iv) microstructure and properties of 3D printed alloys.