Stress Transfer in High Performance Polyethylene Fiber Reinforced Epoxy Resin Composite Analyzed by X-Ray Diffraction. In the Direction Perpendicular to the Fiber Axis.

Abstract Wide-Band Gap (WBG) power devices have become a promising option for high-power applications due to the superior material properties over traditional Silicon. To not limit WBG devices’ mother nature, a rugged and high-performance power device packaging solution is necessary. This study proposes a Double-Side Cooled (DSC) 1.2 kV half-bridge power module having dual epoxy resin insulated metal substrate (eIMS) for solving convectional power module challenges and providing a cost-effective solution. The thermal performance outperforms traditional Alumina (Al2O3) Direct Bonded Copper (DBC) DSC power module due to moderate thermal conductivity (10 W/mK) and thin (120 mm) epoxy resin composite dielectric working as the IMS insulation layer. This novel organic dielectric can withstand high voltage (5 kVAC @ 120 μm) and has a Glass Transition Temperature (Tg) of 300°C, which is suitable for high-power applications. In the thermal-mechanical modeling, the organic DSC power module can pass the thermal cycling test over 1,000 cycles by optimizing the mechanical properties of the encapsulant material. In conclusion, this article not only proposes a competitive organic-based power module but also a methodology of evaluation for thermal and mechanical performance.

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Flexure and bonding behaviour of glass fiber reinforced epoxy resin composite beam under two point loading mechanism.

IOSR Journal of Mechanical and Civil Engineering ◽

10.9790/1684-1402057884 ◽

2017 ◽

Vol 14 (02) ◽

pp. 78-84

Author(s):

Srinath T ◽

Shyam Kumar E

Keyword(s):

Glass Fiber ◽

Epoxy Resin ◽

Composite Beam ◽

Resin Composite ◽

Fiber Reinforced ◽

Glass Fiber Reinforced ◽

Epoxy Resin Composite

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Preferred orientation of high performance carbon fibers

Journal of Materials Research ◽

10.1557/jmr.1992.2612 ◽

1992 ◽

Vol 7 (9) ◽

pp. 2612-2620 ◽

Cited By ~ 4

Author(s):

T. Hamada ◽

M. Furuyama ◽

T. Tomioka ◽

M. Endo

Keyword(s):

Heat Treatment ◽

Carbon Fibers ◽

High Performance ◽

Preferred Orientation ◽

Fiber Axis ◽

Precursor Fiber ◽

X Ray Diffraction ◽

X Ray ◽

Heat Treated ◽

Clear Peak

The preferred orientation of polyacrylnitrile (PAN)-based carbon fibers, mesophase pitch-derived carbon fibers, and pitch precursor fibers was studied by using x-ray diffraction technique. The half width at half maximum (HWHM) intensity of the φ scan x-ray diffraction profiles of these fibers was a minimum at around 2θ = 26°. The result implies that a crystallite with a larger coherence length of crystallite size Lc(002) is better aligned along the fiber axis than that with a smaller Lc(002) in these fibers. Further, θ-2θ scan profiles depending on φ showed that a better aligned crystallite possesses a larger Lc(002) than a misaligned one. Lc(002) of a significantly misoriented crystallite remained constant at about 2 nm even after heat-treatment, though Lc(002) of a well-aligned crystallite was easily changed by heat-treatment for both PAN and pitch-based fibers. The pitch precursor fiber exhibited a clear peak at about 2θ = 7° in the θ-2θ profile and unusual ° scan profiles for 2θ around 7°, which were explained by assuming columnar structures formed by molecule stacking along the c-axis with periodic arrangements of the columns perpendicular to the c-axis. The periodic column stacking structure observed in the pitch precursor fiber was also detected in pitch-based carbon fibers heat-treated at lower temperatures.

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