Evolution of properties of parts during MIM and sintering of recycled oxide particles

ABSTRACT

Metal injection moulding (MIM) is an established process for high volume production of complex shaped metallic parts using commercially available feedstocks. The characteristics of parts after moulding, debinding, and sintering cannot be simply predictable from raw materials because the properties get altered with the process parameters and the corresponding levels of porosity during processing steps. In this study, physical properties, microstructure, and mechanical properties of the MIM parts have been characterised to understand the evolution of strength during various steps in MIM processing. Feedstocks with different binder loading show a considerable difference in physical as well as mechanical characteristics. During sintering of parts which have solid loading of grinding sludge, simultaneous in situ reduction and densification takes place, whereas only densification occurs in carbonyl iron parts. It is, therefore, possible to make complex shaped parts of different levels of porosity from downgraded shop floor metallic waste.

KEYWORDS:

• Shop floor waste
• metal injection moulding
• properties
• in situ reduction
• sintering

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Kedarnath Rane obtained his PhD in Mechanical Engineering from IIT Bombay in 2015. He is presently working as a postdoctoral researcher at Politecnico di Milano since 2017. He is experienced in additive manufacturing, materials testing and sustainable manufacturing processes, with more than 25 cited international scientific publications on these topics, including patents and papers in peer reviewed scientific journals.

Prashant Date is a full professor in the Department of Mechanical Engineering at Indian Institute of Technology Bombay, Mumbai. In the last 25 years, he led several inter-disciplinary R&D projects, guided multiple PhD and Masters students. His area of research involves the design and development of metal and composite forming processes, mechanical metallurgy and powder based manufacturing processes. He shared the relevant knowledge through hundreds of technical papers, invited or conference talks, and training programmes benefiting several hundreds of teachers and working professionals.

ORCID

Kedarnath Rane http://orcid.org/0000-0002-9405-7950

Notes

1 $\mathrm{Degree}\mathrm{of}\mathrm{Reduction}=\left({\displaystyle \frac{\mathrm{Initial}\mathrm{weight}-\mathrm{Final}\mathrm{weight}\mathrm{of}\mathrm{sample}}{\mathrm{Initial}\mathrm{weight}-\mathrm{Theoretical}\mathrm{reduced}\mathrm{weight}}}\right)\times 100\text{\%}$