• Journal of the Korean Society for Heat Treatment
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• v.15 no.3
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• pp.136-141
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• 2002

During warm and hot forging process of steels or aluminum alloys, dies are subject to early fracture, severe wear by thermo-mechanical stress. Especially, during the die-casting of aluminum alloys, the service life of dies is incredibly lowered. In this study we investigated the characteristics of TiBN films produced by PECVD. TiBN films showed very high hardness, excellent wear resistance, which could enhance the service life of die parts such as forging punch, die casting core pin successfully.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.163-164
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• 2009

dc unbalanced magnetron sputtering 방법으로 superhard quarternary Ti-B-C-N films을 합성하였다. XPS, XRD 분석 결과 Ti-B-C-N films은 solid-solution (Ti,C,N)$B_2$와 Ti(C,N) 결정이 amorphous BN에 분포된 나노 복합체를 형성하였다. 여기에서는 film내 N의 양에 따라 강도가 증가하다가 그 후 감소하는 경향을 보였다.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.28-29
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• 1998

• Transactions of the Society of Information Storage Systems
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• v.3 no.3
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• pp.129-134
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• 2007

Boron nitride (BN) is a highly attractive material for wear resistant applications of mechanical components. BN is super hard and it is the second hardest of all known materials. It also has a high thermal stability, high abrasive wear resistance, and in contrast to diamond, BN does not react with ferrous materials. The motivation of this work is to investigate the tribological properties of BN for potential applications in ultra-precision components for data storage, printing, and other precision devices. In this work, the wear characteristics of BN thin films deposited on DLC or Ti buffer layer with silicon substrate using RF-magnetron sputtering technique were analyzed. Wear tests were conducted by using a pin-on-disk type tester and the wear tracks were measured with a surface profiler. Experimental results showed that wear characteristics were dependent on the sputtering conditions and buffer layer. Particularly, BN coated on DLC layer showed better wear resistant behavior. The range of the wear rates for the BN films tested in this work was about 20 to $100{\mu}m^3$/cycle.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.2
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• pp.98-103
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• 2013

The alumina substrates that Ni electrode was printed on and the multi-layered PTCR thermistors of which composition is $(Ba_{0.998}Ce_{0.002})TiO_3+0.001MnCO_3+0.05BN$ were fabricated by a thick film process, and the effect of re-oxidation temperature on their resistivities and resistance jumps were investigated, respectively. Ni electroded alumina substrate and the multi-layered PTC thermistor were sintered at $1150^{\circ}C$ for 2 h under $PO_2=10^{-6}$ Pa and then re-oxidized at $600{\sim}850^{\circ}C$ for 20 min. With increasing the re-oxidation temperature, the room temperature resistivity increased and the resistance jump ($LogR_{290}/R_{25}$) decreased, which seems to be related to the oxidation of Ni electrode. The small sized chip PTC thermistor such as 2012 and 3216 exhibits a nonlinear and rectifying behavior in I-V curve but the large sized chip PTC thermistor such as 4532 and 6532 shows a linear and ohmic behavior. Also, the small sized chip PTC thermistor such as 2012 and 3216 is more dependent on the re-oxidation temperature and easy to be oxidized in comparison with the large sized chip PTC thermistor such as 4532 and 6532. So, the re-oxidation conditions of chip PTC thermistor may be determined by considering the chip size.