• 한국분말재료학회지
• /
• 제4권3호
• /
• pp.188-195
• /
• 1997

In most of sintered metal powder compacts, the sintered density distribution is controlled to be as high and uniform as possible to ensure the required mechanical properties. In general, the density distribution in the compacts is not uniform and not easy to measure. In the present study, a method for measuring the density distribution was developed, based on the indentation force equation by which the hardness and the relative density were related. The indentation force equation, expressed as a function of strength constant, workhardening coefficient and relative density, was obtained by finite element analysis of rigid-ball indentation on sintered powder metal compacts. The present method was verified by comparing the predicted density distribution in the sintered Fe-0.5%C-2%Cu compacts with that obtained by experiments, in which the density distribution was directly measured by machining the compacts from the outer surface progressively.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
• /
• pp.733-734
• /
• 2006

Granulated powders, prepared from PF-5F($D_{50}=4(\mu}m$), PF-10F($D_{50}=6{\mu}m$) and PF-20F($D_{50}=10{\mu}m$) water atomized powder, were compacted, debound and sintered to evaluate the properties of sintered parts. As a result, the relative sintered density of about 97% at sintering temperature of 1423K was obtained. It can be considered that by using granulated finer particle size powder, mechanical properties of sintered parts were also improved.

• 한국세라믹학회지
• /
• 제28권12호
• /
• pp.1019-1025
• /
• 1991

The effect of dissolved Ca ion from plaster mold during slip casting on the microstructure and fracture toughness of high-purity sintered alumina were investigated. When the alumina slip containing 1000 ppm MgO was casted on a calcined alumina mold, the sintered compact had a homogeneous microstructure with equiaxed grains. However, when the same slip was casted on a plaster mold, the sintered compact consisted of the mixture of equiaxed and elongated grains. This inhomogeneous microstructure was also observed in the sintered alumina doped with 100o ppm MgO and 100 ppm CaO whose compact was prepared on the calcined alumina mold indicating that the inhomogeneity was caused by CaO. It was found that the specimen containing both MgO and CaO had higher fracture toughness than that containing MgO only. The enhanced fracture toughness by CaO is probably due to the crack deflection along the boundaries of the elongated grains.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 춘계학술대회
• /
• pp.1225-1230
• /
• 2004

In this paper, the pressure drops were investigated according to the sintered porous wick structure in loop heat pipe(LHP) by theoretical analysis. LHP has the wick only in evaporator for the circulation of working fluid, so utilizes porous wick structure which pore diameter is very small for large capillary force. This paper investigates the effects of different parameters on the pressure drops of the LHP such as particle diameter of sintered porous wick, wick porosity, vapor line diameter, thickness of wick and heating capacity. Working fluid is water and the material of sintered porous wick is copper. According to the these different parameters, capillary pressure, pressure drop in wick were analized by theoretical design method of LHP.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1996년도 춘계학술대회 논문집
• /
• pp.170-176
• /
• 1996

A Sintered carbide roller mold for reflectors which is used for cover of automobile lamp and beacon plate of highway has been developed. The geometry of sintered carbide roller mold has been determined from the analysis of reflector geometry. An acute angle diamond wheel and dressing system also has been designed and developed to manufacture the sintered carbide roller mold.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2017년도 추계 학술논문 발표대회
• /
• pp.225-226
• /
• 2017

Recently, there has been a growing interest in the development of non-sintered binder to reduce CO2 emissions from the cement clinker manufacturing process and a number of studies have been conducted on fly ashes as an industrial by-product. However, in order to utilize fly ashes as a non-sintered binder, it is necessary to solve problems such as safety issues and economical efficiency due to use of an alkali activator. This study evaluates the material properties and compressive strength characteristics of three types of circulating fluidized bed boiler ashes. As a result, it was confirmed that the characteristics of each binder vary depending on the location of the power plant and the types of raw materials. In addition, it has been confirmed that the fluidized bed boiler ash shows a high compressive strength and can be used sufficiently as an non-sintered binder.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
• /
• pp.611-612
• /
• 2006

In a manufacturing technique of the sintered filter, pressureless sintering method has good permeability, it is not need the binder and lubricant used on compacting process, so it has little contamination and it is easy to control the pore size and shape but the mechanical strength is low relatively and it is difficult that parts of complicate form are manufactured. In the case of manufacturing the filter by press and sintering method, in order to be satisfactory characteristic of un-pressed filter, in this study sintered metal filter fabricated by using 30-40mesh stainless steel 316L powder and additive agents. Porosity and structure of pores, permeability and mechanical strength of the sintered filter were investigated with the variation sintering conditions. Porosity was nearly constant about $60{\sim}70%$, density, permeability and mechanical strength were changed markedly with quantity of additive materials and sintering conditions.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
• /
• pp.549-550
• /
• 2006

The corrosion performance of a powder metallurgical aluminum alloy in aeronautical environments was studied for both as sintered and heat treated states. Sintered samples were obtained by uniaxial pressing of an Al-Cu-Mg prealloyed powder followed by liquid phase sintering. The heat treatments applied were T4 and T6. Corrosion behaviour was assessed by means of potentiodynamic polarization. Results for the equivalent commercial wrought counterpart, AA2024-T3, are also presented for comparison. Similar corrosion performance was observed for both as sintered and AA2024-T3 samples, while corrosion resistance of the PM materials was improved by the heat treatment, especially in the T4 state.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
• /
• pp.270-271
• /
• 2006

Nd-Fe-B type powder was sintered using spark plasma sintering method. Fabricated compact sintered at the temperature of $700\;^{\circ}C$, is found to be a composite magnet with Nd-Fe-Co-B and ${\alpha}-Fe$. The compact sintered at $700\;^{\circ}C$ shows slightly low coercivity and large remanent magnetization comparing to the compact sintered at $600^{\circ}C$ due to the formation of ${\alpha}-Fe$ phase, resulting in the large maximum energy product. Maximum energy product tends to decrease with decreasing thickness of sintered compacts below 0.5 mm in thickness.

• 한국군사과학기술학회지
• /
• 제9권2호
• /
• pp.127-135
• /
• 2006

Experimental studies of the cylindrical sintered-copper wick heat pipes were carried out to investigate the capillary heat transfer characteristics. Six models of the sintered-copper wick heat pipes were manufactured and tested to evaluate the heat transport limitations and the thermal characteristics. Also the performance of the heat pipes was analyzed theoretically and compared with the test results. The heat pipe models are divided into two sintered-wick groups and the nominal particle sizes are $180{\mu}m$(wick #1) and $200{\mu}m$(wick #2) respectively The experimental results showed that, the porosity of wick #1 was higher than that of wick #2, and also the wick #1 was generally superior than the wick #2 for the heat transport capability. The maximum heat transport rates were increased as the wick thicknesses and the vapor temperatures were increased.