Sintering shrinkage of uniaxial cold compacted iron: influence of the microstructure on the anisothermal and isothermal shrinkage of uniaxial cold-compacted iron

ABSTRACT

The influence of the microstructure of uniaxial cold-compacted green iron on the sintering shrinkage was investigated. Pores in the green parts are very slightly oriented, while the dimension of the interparticle contact areas is anisotropic. A large and anisotropic anisothermal shrinkage in alpha iron was measured, greater than isothermal shrinkage at the 1120°C. The results were interpreted on the basis of the geometrical and of the structural activity, and the effective diffusivity responsible for neck growth was determined.

KEYWORDS:

• Shrinkage
• microstructure
• anisotropy

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

S. Baselli received the MSc in Materials and Industrial Production Engineering in 2016 from University of Trento and is currently PhD student at the Department of Industrial Engineering, Trento University.

E. Torresani received the PhD in Materials, Mechatronics and System Engineering in 2016 from University of Trento and is currently Post-Doc fellow at the San Diego State University, Department of Mechanical Engineering.

M. Zago received the MSc in Materials and Industrial Production Engineering in 2016 from University of Trento and is currently PhD student at the Department of Industrial Engineering, Trento University.

S. Amirabdollahian received MSc in Materials Science and Engineering in 2014 from University of Trento and is currently research assistant at the Department of Industrial Engineering, Trento University.

I. Cristofolini received the Ph.D. degree in Metallurgical Engineering in 1995 from Padua University, Italy. She is currently associate professor of the Department of Industrial Engineering, Trento University, in the field Design methods for industrial engineering. Her main research activity is devoted to the study of design methods for powder metallurgy, to design methods against wear, to PM parts geometric dimensioning and tolerancing.

A. Molinari received the Ph.D. degree in Metallurgical Engineering in 1986 from Torino technical University, Italy. He is currently a full professor of the Department of Industrial Engineering, Trento University. His main research activity is devoted to the study of mechanisms of cold compaction and of sintering of metallic powders, to mechanical and wear properties of sintered steels, to the application of AM in medical industry. He received Honor Ph.D. by University Carlos III, Madrid in 2016 and is Fellow of EPMA and of APMI.