Flow behavior of magnetic steel powder
| Autor: | Christopher Neil Hulme |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Powder metals Magnetism General Chemical Engineering flowability Compressive strength Particles sizes Magnetization Cohesive force Shear flow Powder-based Van der Waals forces Powder metallurgy Spreadability spreadability Metallurgy and Metallic Materials Manufacturing Surface and Joining Technology Flow behaviours Composite material Bearbetnings- yt- och fogningsteknik X ray diffraction analysis Magnetic steel Steel powder Particle size Flow measurement Flow (mathematics) magnetism Dual-phases steels Metallurgi och metalliska material Flowmeters |
| Zdroj: | Particulate Science and Technology. 40:576-588 |
| ISSN: | 1548-0046 0272-6351 |
| DOI: | 10.1080/02726351.2021.1977442 |
| Popis: | Flow occurs in most powder-based processes, opposed by various cohesive forces. Magnetism is often overlooked for metal powders. Here, flowability and magnetization were measured for a dual-phase steel powder in size fractions from (Formula presented.) to > 200 µm. The finest fraction did not flow through a Hall flowmeter, then flow time increased continuously with particle size from 12 ± 1 s for the next fraction ((Formula presented.)) to > 28 ± 0.5 s for > 200 µm. Drying had little effect. Key metrics derived from shear tests gave no overall relationship between flow behavior and particle size. Magnetism was considered the most likely reason for this behavior. Magnetometry showed a remanent magnetization of (Formula presented.) which causes ∼ 5 µN cohesion between 200 µm diameter particles. X-ray diffractometry showed that the powder contained 77 wt%-80 wt% of (magnetic) martensite. Liquid bridging, van der Waals forces and friction (in the Hall flowmeter geometry) contribute 50 µN, 0.08 µN and 4 µN, respectively, to cohesion in 200 µm particles. These results can be used to help explain flow behavior in other magnetic powders and allow optimization of powders and/or powder-based processes. QC 20220504 |
| Databáze: | OpenAIRE |
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