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The Neck to Particle Ratio Effect on the Mechanical and Morphological Sintering Features of Porous Stainless Steel (SS) Hollow Fibers
Author(s) -
SchmedaLopez Diego R.,
Nunes Eduardo H. M.,
Vasconcelos Daniela,
Vasconcelos Wander L.,
Meulenberg Wilhelm A.,
Diniz da Costa João C.
Publication year - 2018
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201800045
Subject(s) - materials science , sintering , composite material , porosity , coalescence (physics) , particle size , void (composites) , particle (ecology) , chemical engineering , oceanography , physics , astrobiology , engineering , geology
The SS hollow fibers are prepared by extruding a mixture of SS particles and a polymeric binder in a phase inversion process followed by sintering at various temperatures (950–1100 °C), resulting in the formation of void structures with a finger‐like inner shell and a sponge‐like outer shell. The mechanical strength increases by over 1000% as the SS particle size decreases from D 50 = 32 to 4 μm, and by ≈150% as the sintering temperature increases from 950 to 1100 °C. The best mechanical strength reached is 820 MPa for the D 50 = 4 μm SS hollow fiber sintered at 1100 °C. The neck to particle (N/P) ratio proves to be a morphological measurement with good correlation with the mechanical properties of the SS hollow fibers. The mechanical strength increases by ≈44% (sintering effect) and ≈92% (particle size effect) from a N/P ratio of ≈0.8 to 0.9 for the smaller SS particle hollow fiber. At this ratio, the necks for the particles are in close contact and at the boundary of full coalescence, thus at the onset of fast mass transfer and grain formation/growth as diffusion increases significantly by six order of magnitude.