HEEJAE SHIN

Prof. Dr. HEEJAE SHIN


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
29 February 2020 in Nanomaterials
Verified
Journal Article
Open access
PDF file
HKHong Gun Kim
Hong Gun Kim
SGSunho Go
Sunho Go
HSHEEJAE SHIN
HEEJAE SHIN
LKLee-Ku Kwac
Lee-Ku Kwac
HKHong-Gun Kim
Hong-Gun Kim
This paper aims to investigate different properties of the Fe-Al matrix reinforced with multi-walled carbon nanotube (MWCNT) nanocomposites with the Al volume content up to 65%, according to the Fe-Al combination. In addition, the effect of adding Co content on the improvement of the soft magnetic properties of the nanocomposites was carried out. The nanocomposites were fabricated using the powder metallurgy process. The iron-aluminum metal matrix reinforced multi-walled carbon nanotube (Fe-Al-MWCNT) nanocomposites showed a continuous increase of saturation magnetization from 90.70 A·m2/kg to 167.22 A·m2/kg and microhardness, whereas the electrical resistivity dropped as the Al content increased. The incorporation of Co nanoparticles in Fe-Al-MWCNT up to 35 vol% of Co considerably improved the soft magnetic properties of the nanocomposites by reducing the coercivity and retentivity up to 42% and 47%, respectively. The results showed that Al-based magnetic nanocomposites with a high Al volume content can be tailored using ferromagnetic particles. The composites with a volume content of magnetic particles (Fe+Co) greater than 60 vol% exhibited higher saturation magnetization, higher coercivity, and higher retentivity than the standard Sendust core. Moreover, the produced composites can be used for the lightweight magnetic core in electromagnetic devices due to their low density and good magnetic and mechanical properties.

11 October 2020 in Polymers
Verified
Journal Article
Open access
PDF file
ATAlexandre Tugirumubano
Alexandre Tugirumubano
SGSunho Go
Sunho Go
HSHEEJAE SHIN
HEEJAE SHIN
LKLee-Ku Kwac
Lee-Ku Kwac
HKHong-Gun Kim
Hong-Gun Kim
In this work, we aimed to manufacture and characterize carbon-fiber–polymer–metal-particles magnetic composites with a sandwichlike structure. The composites were manufactured by stacking the plain woven carbon fiber prepregs (or carbon-fiber-reinforced polymers (CFRP)) and layers of the FeSi particles. The layer of FeSi particles were formed by evenly distributing the FeSi powder on the surface of carbon fiber prepreg sheet. The composites were found to have better magnetic properties when the magnetic field were applied in in-plane (0°) rather than in through-thickness (90°), and the highest saturation magnetization of 149.71 A.m2/kg was achieved. The best inductance and permeability of 12.2 μH and 13.08 were achieved. The composites obviously exhibited mechanical strength that was good but lower than that of CFRP composite. The lowest tensile strength and lowest flexural strength were 306.98 MPa and 855.53 MPa, which correspond to 39.58% and 59.83% of the tensile strength and flexural strength of CFRP (four layers), respectively.

16 July 2020 in Metals
Verified
Journal Article
Open access
PDF file
HKHong Gun Kim
Hong Gun Kim
SGSunho Go
Sunho Go
LKLee-Ku Kwac
Lee-Ku Kwac
HSHEEJAE SHIN
HEEJAE SHIN
HKHong-Gun Kim
Hong-Gun Kim
In this paper, the liquid phase sintering was performed using spark plasma sintering to produce iron (Fe: 80 vol%)–aluminum (Al)–multi-walled carbon nanotubes (MWCNTs) magnetic hybrid metal matrix nanocomposites. The properties of the nanocomposites were investigated by considering different parameters of materials processing. The reinforcement of MWCNT with a content of 0–2 vol% did not affect the saturation magnetization of the nanocomposites but increased the coercivity and reduced both the electrical resistivity and the mechanical transverse rupture strength. It was found that milling the powders for 24 h resulted in composite with high saturation magnetization (148.820 A·m2/kg) and high coercivity (2175.6 A/m) but further milling time had reduced the values of magnetic properties. The mixture of Fe nanoparticles and Fe microparticles in composites with a nanoparticles-to-microparticles volume ratio of 1:1 has led to the enhanced saturation magnetization up to 157.820 A·m2/kg and reduced the coercivity of 50.20% in comparison with the Fe nanoparticles based nanocomposites. That mixture exhibited good electrical resistivity but caused the reduction of mechanical strength. The post-sintering annealing has significantly improved the magnetic softness of the composites by reducing the coercivity up to 854.30 A/m and increased the saturation magnetization.