Functionally graded materials fabricated by spark plasma sintering process for energy conversion applications

Time 2018-11-09 11:30~11:55 Place Rm.600A
Code No. DP-O13 Session Chair
Name Prof. Hansang Kwon
Affiliation Pukyong National University
Title Functionally graded materials fabricated by spark plasma sintering process for energy conversion applications
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CountryKorea
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AffiliationPukyong National University
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Co-author-2PrefixMr.
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Co-author-3PrefixMs.
CountryKorea
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AffiliationPukyong National University
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Contents
The adoption of solid-state lighting (SSL) technology is spreading gradually into the modern industrial world as well as into indoor and outdoor lighting because of the associated energy savings. A state-of-the-art SSL device comprises blue light-emitting diodes (LEDs) covered with a yellow-emitting phosphor. The ceramic phosphor converts part of the blue light to yellow light, and the resulting mixture of blue and yellow light creates white light. Thermal stability is an essential requirement for the phosphor in high-power white lighting because the phosphor is constantly irradiated with high-power blue light, which causes thermal degradation. Functionally graded metal-ceramic adapting the concept of the functionally graded materials (FGMs); aluminum (Al) is selected as a metal and ceramic phosphor is fabricated by a simple powder process through spark plasma sintering (SPS) [1]. The phosphor layer contains some glass powder, and the thermally graded layer is positioned between the phosphor and Al layers. We achieve a high thermal conductivity in the FGMs, which is twenty times that of the reference sample (1.5 W·m-1·K-1). Consequently, our composite exhibits excellent thermal stability in luminous flux and chromaticity under a 4 W blue laser diode (LD). We anticipate that our composite materials and system could be applied to energy-saving systems, such as electric vehicles and industrial lighting.