Influence of milling media on the structure and agglomeration behaviour of some hardmetal powder

ABSTRACT

This paper presents the influence of milling media on the structure and morphology of WC–Co powders for sintered tools. WC–Co powders have been milled in two different organic media, acetone and isohexane. The characterisation of the as-milled samples has been done by X-ray diffraction, scanning electron microscopy (SEM) and differential scanning calorimetry. The mean crystallite size decreases with milling time for the samples processed in acetone, while in the case of isohexane, the crystallite size stays at a relatively constant value when increasing the milling duration. The calculated mean crystallite size is below 50 nm for any milling duration, with larger values for acetone (16–46 nm) as compared to isohexane samples (10–12 nm). The SEM revealed that the dried powder is composed of agglomerated submicronic particles, and at high magnification, the presence of nanoparticles is noticed. The density of the aggregates was linked to the polarity of the solvents, which influences the sedimentation kinetics.

KEYWORDS:

• WC–Co composite
• acetone
• isohexane
• milling
• polar solvent
• drying
• agglomerate

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Mr. H. F. Chicinaş is a PhD student at the Department of Materials Science and Technology, Technical University of Cluj-Napoca. Horea Florin does research in powder metallurgy with focus on the milling of hardmetal powders.

Mr. D. O. Jucan is a master student at the Department of Materials Science and Technology, Technical University of Cluj-Napoca.

Dr. T. F. Marinca is a lecturer at the Department of Materials Science and Technology, Technical University of Cluj-Napoca. His research is mainly focused on mechanosynthesis and magnetic ferrites.

Dr. B. V. Neamțu is a lecturer at the Department of Materials Science and Technology, Technical University of Cluj-Napoca. His research is focused on mechanosynthesis and amorphous magnetic materials.

Dr. G. Contiu is a lecturer at Manufacturing Engineering Department, Technical University of Cluj-Napoca.

Mr. P. Gotze is working at G-Elit Prazisionwerkzeug in the R & D department. His areas of expertise include synthesis and characterisation of cemented carbides.

Dr. A. Eckert is the head of the R & D department of G-Elit Prazisionwerkzeug. Dr. Eckert has a vast experience and knowledge in the manufacturing of cemented carbides.

Dr. C.O. Popa is a materials science professor at the Department of Materials Science and Technology, Technical University of Cluj-Napoca. His areas of expertise include materials characterisation and biomaterials.

ORCID

H. F. Chicinaş http://orcid.org/0000-0001-7150-8029

T. F. Marinca http://orcid.org/0000-0002-5531-5451

B. V. Neamțu http://orcid.org/0000-0003-0666-8303

P. Götze http://orcid.org/0000-0003-1500-9430

A. Eckert http://orcid.org/0000-0003-2053-6040

Additional information

Funding

This work was made possible by the generous support of Gühring Company.