Characterization of die pressed green compacts

Date

1997-01-01

Author

Özkan, Necati

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

138
views

0
downloads

Die-pressed agglomerated alumina compacts, prepared as cylinders using single-ended nominally uniaxial compressive stresses, have been characterized by measuring their strength and density distributions. The strength of the alumina compacts, measured using the Brazilian configuration, increases up to an optimum compaction pressure, upon further increasing the compaction pressure, the strength of the green compacts decreases due to the formation of internal cracks. The density distributions in the alumina compacts have also been determined experimentally, using the coloured layer technique and also deduced indirectly from hardness measurements. The results obtained from these two experiments are shown to be in good agreement. The densest parts of the compacts, compressed uniaxially from the top planar surface adjacent to the compression source, are at the outer circumference at the top and the least dense parts are at the outer circumference at the bottom face. The density near the cylindrical surface of the compacts decreases with height from the top to the bottom of the compact. The density difference between the most dense and the least dense parts of the compacts increases with increasing aspect ratio, that is, the height-to-diameter patio. The density distributions in the alumina compacts have also been estimated using a first-order predictive model. According to this model, the mean density variation along the height of the compact decreases linearly with height from the top to the bottom of the compact. These predictions are shown to be almost in accord with experiment.

URI

https://hdl.handle.net/11511/30720

Journal

Journal Of The European Ceramic Society

DOI

https://doi.org/10.1016/s0955-2219(96)00090-8

Collections

Graduate School of Natural and Applied Sciences, Article

Suggestions

OpenMETU
Core

Evaluation of fluctuating pressures measured with connection tubes Aydın, İsmail (1998-01-01) The dynamic characteristics of fluctuating pressure measuring systems composed of connection tubing and pressure transducers were analyzed. A method of correction for the effects of resonance and viscous damping on the measured pressure fluctuations was proposed. A mathematical model of the measuring system was formed combining the governing equations of the unsteady flow in the rigid connection tubing and the corresponding volumetric deformation in the transducer. Numerical solution of the governing equati...
Determination of mechanical properties of hybrid fiber reinforced concrete Yurtseven, Alp Eren; Tokyay, Mustafa; Department of Civil Engineering (2004) Fiber reinforcement is commonly used to provide toughness and ductility to brittle cementitious matrices. Reinforcement of concrete with a single type of fiber may improve the desired properties to a limited level. A composite is termed as hybrid, if two or more types of fibers are rationally combined to produce a composite that derives benefits from each of the individual fibers and exhibits a synergetic response. This study aims to characterize and quantify the mechanical properties of hybrid fiber reinfo...
Study of sol-gel processing for fabrication of low density alumina microspheres Dilsiz, N; Akovali, G (2002-07-01) A sol-gel process for producing microspheres of low density alumina has been developed. A Dispal alumina sol and aluminum monohydrate were used as starting materials. Microspheres with spherical shape and controllable size have been produced by using a drop generation technique, The technique consists of producing a continuous stream Of uniform droplets of alumina sol and then converting the drops into a rigid form by exposing them to an ammonium hydroxide gelation medium. By using this technique. alumina s...
Construction of phase diagrams to estimate phase transitions at high pressures: A critical point at the solid liquid transition for benzene Ibrahimoglu, Beycan; Üner, Deniz; Veziroglu, Ayfer; Karakaya, Fuat; Ibrahimoglu, Beycan (2021-04-01) Phase diagrams are an integral part of the estimation of material properties in the case of high temperature and pressure. The pressure-temperature (P-T) phase diagram is used to determine the state of aggregation (solid, liquid, gaseous) of a substance under given conditions. This article presents a method to reveal new states in the phase diagram, including the possibility of the plasma state. Using the empirical data of benzene, a critical pressure beyond solid-liquid equilibrium was estimated. It is hig...
Unprecedented irradiation resistance of nanocrystalline tungsten with equiaxed nanocrystalline grains to dislocation loop accumulation El-Atwani, O.; Esquivel, E.; Aydoğan Güngör, Eda; Martinez, E.; Baldwin, J. K.; Li, M.; Uberuaga, B. P.; Maloy, S. A. (Elsevier BV, 2019-02-01) Nanocrystalline metals are often postulated as irradiation tolerant materials due to higher grain boundary densities. The efficiency of these materials in mitigating irradiation damage is still under investigation. Here, we present an in-situ transmission electron microscopy with ion irradiation study on equiaxed 35 nm grained tungsten (NCW-35 nm) and compare its radiation tolerance, in terms of dislocation loop damage, to several other grades of tungsten with different grain sizes at two temperatures (RT a...

Citation Formats

N. Özkan, “Characterization of die pressed green compacts,” Journal Of The European Ceramic Society, pp. 697–711, 1997, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30720.