Characterisation of the mechanisms taking place during liquid phase sintering of PM boron steels with the help of artificial intelligence

ABSTRACT

Liquid phase sintering (LPS) of powder metallurgy (PM) components is a well-recognised strategy to enhance the densification of pressed-and-sintered compacts. This work reports the investigation on the liquid phase formation when a Fe–Ni–Mn–C–B master alloy (MA) is used as a boron carrier in combination with two iron base powders pre-alloyed with Mo. Through differential scanning calorimetry tests, quantitation of the microstructure with the help of artificial intelligence, as well as measurement of sintered density and strength as a function of sintering temperature, it was possible to unravel the mechanisms that take place before and during LPS. It was confirmed that a cascade of events takes place in the solid state prior to reaching the temperature necessary for a eutectic reaction to form a liquid. Additionally, the pre-alloyed Mo content was identified as a factor that modifies the initiation of LPS but not the LPS mechanisms per se.

KEYWORDS:

• Boron PM steels
• liquid phase sintering
• artificial intelligence
• rearrangement
• dissolution–reprecipitation
• master alloy
• densification

Disclosure statement

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

Data availability statement

The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Additional information

Funding

The authors are very grateful to the Natural Sciences and Engineering Research Council of Canada (NSERC) for providing financial resources for this work [grant number #RGPIN-2018-04533].

Notes on contributors

Simon Gélinas

Simon Gélinas graduated from materials and metallurgical engineering at Université Laval, Québec, Canada, where he also did his PhD thesis working on liquid phase sintering for press-and-sinter compacts. He now works as a Research Associate, focusing on projects revolving around the production, the characterization and the utilization of metal powders for additive manufacturing.

Carl Blais

Carl Blais is a full professor in the program of materials and metallurgical engineering at Université Laval, Québec, Canada. His principal fields of interest are related to the development of metal powders for the various manufacturing processes that use metal powders as raw materials.