• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.257-260
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• 1999

It is very important to design the shape of container in HIPing process since the final shape and relative density distribution of the product are decisively dependent on the shape of container. A derivative based approach to determine the shape of container in HIPing process is presented. In this approach the optimal design problem is formulated on the basis of the finite element process. The process model the formulation for process optimal design and the schemes for the evaluation of the design sensitivity and an iterative procedure for optimization are described. In comparison with finite difference scheme the validity of the schemes for the evaluation of the design sensitivity is examined.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.461-470
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• 2002

The present paper investigates the effect of hot isostatic pressing (HIPing) on mechanical properties, e.g., tensile strength, ductility and impact absorption energy of sand and die casted aluminum alloys. After HIPing at various temperatures and pressure conditions, uniaxial tensile test and Izod impact test of the samples were carried out. The experimental results showed improvements in uniaxial tensile strength, elongation and Izod impact toughness of sand casted aluminum alloy, while deterioration of a tensile strength fur die casted aluminum alloy. The effect of HIPing for microstructure of the cast aluminum alloy was also investigated.

• Journal of the Korean Ceramic Society
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• v.28 no.9
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• pp.696-704
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• 1991

ZrO2-Toughened Alumina-Ceramics (ZTA) with SiC Whisker as dispersive additive were prepared by pressureless sintering at 1$600^{\circ}C$ and 1$650^{\circ}C$ and by HIPing at 1$600^{\circ}C$ in Ar atmosphere. Effects of SiC-Whisker addition on microstuructural, mechanical, and thermal properties were investigated and the toughening mechanisms between theory and experiment were compared. Specimens with 15 vol% Whisker prepared by HIPing showed 8.26 MPa.ma1/2 in fracture toughness and 600 MPa in flexural strength owing to contribution of the three mechanisms such as crack deflection, whisker bridging and whisker pullout in spite of difference between the theoretical and experimental values due to the partial inhomogeneous dispersion of SiC-Whisker in the matrix and the processing flaw.

• The Korean Journal of Ceramics
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• v.5 no.1
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• pp.73-77
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• 1999

Capsule free hot isostatic pressing (HIPing) of 12 mol% $CeO_2-88 mo% ZrO_2 (12CeO_2-88ZrO_2)$ powder was conducted at 1100~$1200^{\circ}C$ using the powder crystallized in supercritical methanol followed by supercritical drying. Porous $12CeO_2-88ZrO_2$ ceramics with ~35% open porosity, micropore diameter of ~23 nm and a narrow pore size distribution were fabricated by capsule free hot isostatic pressing at $1100^{\circ}C$. The porosity increased with decrease in HIPing temperature and was accompanied by a steady decrease in fracture strength.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.05a
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• pp.17-19
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• 1988

$YBa_2Cu_3O_{7-x}$ oxide superconductors were fabricated by the hot isostatic pressing (HIP). It was shown that their structures were orthorombic and constited of a single (123) phase. While as-sintered compacts had many pores, they were remarkably reduced by Hiping. The on-set and off set temperature of (123) compound sintered at $950^{\circ}C$ in oxygen and hiping at $880^{\circ}C$ were the highest and it showed 0 resistance at $90^{\circ}K$. The critical current density ($J_c$) of the above superconductor was $27A/cm^2$ and it also showed a number of twin structures, which are typical of high $T_c$ superconductor. It seemed that the low current density may be due to the many pores of starting-sintered compacts.

• Journal of Powder Materials
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• v.20 no.4
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• pp.264-268
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• 2013

Nickel-based superalloy IN 713C powders have been consolidated by hot isostatic pressing (HIPing). The microstructure and mechanical properties of the superalloys were investigated at the HIPing temperature ranging from $1030^{\circ}C$ to $1230^{\circ}C$. When the IN 713C powder was heated above ${\gamma}^{\prime}$ solvus temperature (about $1180^{\circ}C$), the microstructure was composed of the austenitic FCC matrix phase ${\gamma}$ plus a variety of secondary phases, such as ${\gamma}^{\prime}$ precipitates in ${\gamma}$ matrix and MC carbides at grain boundaries. The yield and tensile strengths of HIPed specimens at room temperature were decreased while the elongation and reduction of area were increased as the processing temperature increased. At $700^{\circ}C$, the strength was similar regardless of HIPing temperature; however, the ductility was drastically increased with increasing the temperature. It is considered that these properties compared to those of cast products are originated from the homogeneity of microstructure obtained from a PM process.

• Journal of the Speleological Society of Korea
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• no.76
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• pp.61-66
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• 2006

The present report is the investigation of the effects of the HIP treatment on plasma-sprayed ceramic coating of $Al_2O_3$, $Al_2O_3-SiO_2$ on the metal substrate. These effects were characterized by phase identification, Vickers hardness measurement, and tensile test before and after HIPing.

• Journal of Powder Materials
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• v.5 no.4
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• pp.279-285
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• 1998

The microstructures and mechanical properties of submicron WC-Co cemented carbides were investigated in relation to cobalt content. To inhibit the WC grain growth during sintering, VC was added as a inhibitor in each alloy with 3 mass% to the cobalt content. The WC-(5, 8, 10, 15, 20) mass% Co compacts were sintered at $1400^{\circ}C$ for 30 min in vacuum. Some of WC-(5, 8, 10) mass% Co sintered compacts were HIPed with 120 atm at 130$0^{\circ}C$ for 1 hr. The shrinkages of all HIPed alloys were increased without depending on the cobalt contents and the sintered densities of them. The relative densities of the alloys were increased with the cobalt content and HIPing. The less the cobalt content, the larger the WC grain. Many contiguities of WC grains were found in WC-5 mass% Co alloy. The sizes and numbers of pores in the alloys were decreased by HIPing. And also the strength and the hardness of each alloy were increased. The maximum hardness was about 18.95 GPa in the WC-5 mass% Co alloy HIPed and the maximum transverse-rupture strength (T.R.S.) 3.2 GPa in the WC-20 mass% Co alloy sintered.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.93-95
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• 2004

The present report is the investigation of the effects of the HIP treatment on plasma-sprayed ceramic coating of $Al_2$O$_3$, $Al_2$O$_3$- SiO$_2$ on the metal substrate. These effects were characterized by phase identification, Vickers hardness measurement, and tensile test before and after HIPing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.336-339
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• 2003

The present report is the investigation of the effects of the HIP treatment on plasma-sprayed ceramic coating of $Al_2O_3$, $Al_2O_3-SiO_2$ on the metal substrate. These effects were characterized by phase identification, Vickers hardness measurement, and tensile test before and after HIPing.