Effect of powder particle shape and size distributions on the properties of low-viscosity iron-based feedstocks used in low-pressure powder injection moulding

ABSTRACT

Low-pressure powder injection moulding (LPIM) is a cost-effective manufacturing technology used to fabricate complex-shaped parts with high mechanical properties at low- or high-volume production. This research work presents an experimental approach to investigate the debound/sintered properties of iron components produced by the LPIM process using iron-based powders exhibiting different particle shapes and size distributions. Four low-viscosity feedstocks were mixed and injected into a rectangular mould cavity before being thermally wick-debound and finally sintered using identical debinding and sintering cycles. This study confirms that both irregular and spherical iron powders can be shaped via the LPIM process. The solid loadings obtained with these two powder morphologies, varying from 58 to 62 vol.-%, represent expected values. The trend in the density values obtained with irregular (∼6.6 g/cm³) and spherical (∼7.5 g/cm³) powders was validated by metallographic observations.

KEYWORDS:

• Low-pressure powder injection moulding (LPIM)
• thermal wick debinding
• pre-sintering temperature
• sintering
• iron powder
• irregular particles

Acknowledgements

The authors wish to thank Mr. Raphael Cote and Mr. Francis Ares for their collaboration in TGA and injection tests.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Natural Sciences and Engineering Research Council of Canada: [Grant Number CRDPJ505289-16].

Notes on contributors

Seyed Mohammad Majdi

Seyed Mohammad Majdi is a master student at Ecole de technologie superieure (ÉTS) and he completed his bachelor study in polymer engineering at Shiraz Azad University, Iran, in 2013. Powder and polymer characterisations, debinding and sintering are among his research interests.

Atefeh Ayatollahi Tafti

Atefeh Ayatollahi Tafti is a PhD candidate at Ecole de technologie superieure (ÉTS) and she completed her master studies in material science and engineering at University of Technology Malaysia (UTM) in 2016. Her research interests include material characterisation, powder processing, sintering and manufacturing using novel techniques.

Vincent Demers

Vincent Demers is a Professor in Department of Mechanical Engineering of Ecole de technologie superieure since 2014. He works in the development of advanced manufacturing technologies with expertise in the field of powder metallurgy, brazing, welding and heat treatment. His research and teaching interests include materials science, materials characterisation and manufacturing technologies.

Guillem Vachon

Guillem Vachon is a research engineering at Rio Tinto Iron & Titanium Technology Center since 2018. He received his master’s degree in Metallurgical Engineering in 2005 from Laval University. He is an expert in the development of new powder applications, welding technology, foundry casting and electronic assembly.

Vladimir Brailovski

Vladimir Brailovski is a Professor of Mechanical Engineering at ÉTS (Montreal, Canada). He works on multidisciplinary projects requiring expertise in the fields of materials, design and manufacturing processes. Since the last 5 years, he is particularly interested in powder characterisation and 3D printing of high added-value metal components for medicine and aerospace.