• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.314-319
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• 2004

High temperature fracture toughness characteristics of shot peened spring steel(SUP-9), which is used for automobile suspension system and railroad, was investigated in this paper. Fracture tougness test for room temperature, $100^{\circ}C$ , and $200^{\circ}C$ were evaluated by material test system(MTS). The experimental results show that the fracture toughness was improved by peened and unpeened. The fracture toughness for high temperature were also improved by peened and unpeened.

• 한국세라믹학회지
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• 제45권2호
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• pp.105-111
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• 2008

Symmetric three layer composites have been prepared by freeze casting and then pressureless sintered at $l700-1800^{\circ}C$ in $N_2$ gas atmosphere. The relative sintered density of multilayer composites having microstructural characteristics of later intermediate-stage densification increased with sintering temperature and reached about 95% theoretical value at $1800^{\circ}C$. Although the indentation strength of the multilayer composites was generally reduced with increasing Vickers indentation load up to 294N, the damage resistance of multilayer composites was superior compared to monolithic layer 95AL/5SN material. The three-point bend strength of the layered materials remained at the values 266-298 MPa after indentation with a load of 49N, while that of the monolithic 95AL/5SN material was 219 MPa. The fracture toughness of the multilayer material was $5.4-6.6\;MPa\;m^{1/2}$.