Sinter-forging of nanophase TiO sub 2

Uchic, M; Hofler, H J; Flick, W J; Tao, R; Averback, R S; Kurath, P

Title: Sinter-forging of nanophase TiO sub 2

Full Record
Other Related Research

Abstract

Considerable effort has been directed in recent years to developing ceramic materials that can be both sintered to full density at low temperatures and processed by superplastic forming. One strategy for achieving this goal has been to reduce the particle size of the starting powder, and by anaphase processing, particles of sizes less than {approx}10 nm can now be realized. Indeed, recent studies on nanophase ceramics have demonstrated that sintering temperatures can be reduced dramatically and that nanophase ceramics have excellent potential for superplastic forming. Nevertheless, the grain growth that occurs during the processing of these new materials restricts their applicability. In nanophase (n-) TiO{sub 2}, some progress in controlling grain size has been achieved by using dopants or hot pressing. Sinter-forging offers another means to achieve this goal, although this method has been applied mostly to materials with larger grains. Studies of sinter-forging are also useful for elucidating the mechanisms of sintering and creep in ceramic materials. In the present paper, the authors examine the characteristics of sinter-forging in n-TiO{sub 2}. Only limited studies of sinter-forging have thus far been performed on well characterized powders of comparable size, and even these had a somewhat larger grain size.

Authors:

Uchic, M; Hofler, H J; Flick, W J; Tao, R; Averback, R S ^[1]; Kurath, P ^[2]

Illinois Univ., Urbana, IL (United States). Dept. of Materials Science and Engineering
Illinois Univ., Urbana, IL (United States). Dept. of Mechanical Engineering

Publication Date:: Sun Mar 01 00:00:00 EST 1992

OSTI Identifier:: 5577213

Resource Type:: Journal Article

Journal Name:: Scripta Metallurgica; (United States)

Additional Journal Information:: Journal Volume: 26:5; Journal ID: ISSN 0036-9748

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; POWDERS; PARTICLE SIZE; TITANIUM OXIDES; FORGING; PLASTICITY; SINTERING; THERMODYNAMIC PROPERTIES; DENSITY; GRAIN BOUNDARIES; PROCESS CONTROL; SUPERLATTICES; CHALCOGENIDES; CONTROL; CRYSTAL STRUCTURE; FABRICATION; MATERIALS WORKING; MECHANICAL PROPERTIES; MICROSTRUCTURE; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; SIZE; TITANIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS; 360203* - Ceramics, Cermets, & Refractories- Mechanical Properties; 360202 - Ceramics, Cermets, & Refractories- Structure & Phase Studies; 360204 - Ceramics, Cermets, & Refractories- Physical Properties; 360201 - Ceramics, Cermets, & Refractories- Preparation & Fabrication

Citation Formats


                    Uchic, M, Hofler, H J, Flick, W J, Tao, R, Averback, R S, and Kurath, P. Sinter-forging of nanophase TiO sub 2.  United States: N. p., 1992. 
        Web.

Copy to clipboard


                    Uchic, M, Hofler, H J, Flick, W J, Tao, R, Averback, R S, & Kurath, P. Sinter-forging of nanophase TiO sub 2.  United States.

Copy to clipboard


                    Uchic, M, Hofler, H J, Flick, W J, Tao, R, Averback, R S, and Kurath, P. 1992.  
        "Sinter-forging of nanophase TiO sub 2".  United States.

Copy to clipboard


                    
@article{osti_5577213,

  title        = {Sinter-forging of nanophase TiO sub 2},

  author       = {Uchic, M and Hofler, H J and Flick, W J and Tao, R and Averback, R S and Kurath, P},

  abstractNote = {Considerable effort has been directed in recent years to developing ceramic materials that can be both sintered to full density at low temperatures and processed by superplastic forming. One strategy for achieving this goal has been to reduce the particle size of the starting powder, and by anaphase processing, particles of sizes less than {approx}10 nm can now be realized. Indeed, recent studies on nanophase ceramics have demonstrated that sintering temperatures can be reduced dramatically and that nanophase ceramics have excellent potential for superplastic forming. Nevertheless, the grain growth that occurs during the processing of these new materials restricts their applicability. In nanophase (n-) TiO{sub 2}, some progress in controlling grain size has been achieved by using dopants or hot pressing. Sinter-forging offers another means to achieve this goal, although this method has been applied mostly to materials with larger grains. Studies of sinter-forging are also useful for elucidating the mechanisms of sintering and creep in ceramic materials. In the present paper, the authors examine the characteristics of sinter-forging in n-TiO{sub 2}. Only limited studies of sinter-forging have thus far been performed on well characterized powders of comparable size, and even these had a somewhat larger grain size.},

  doi          = {},

  url          = {https://www.osti.gov/biblio/5577213},
  journal      = {Scripta Metallurgica; (United States)},

  issn         = {0036-9748},

  number       = ,

  volume       = 26:5,

  place        = {United States},

  year         = {Sun Mar 01 00:00:00 EST 1992},

  month        = {Sun Mar 01 00:00:00 EST 1992}

}

Copy to clipboard

Journal Article:

Other availability

Find in Google Scholar

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

Processing and properties of nanophase oxides

Conference Eastman, J; Liao, Y; Narayanasamy, A; ...

Nanophase oxides (Al{sub 2}O{sub 3}, MgO, ZnO and TiO{sub 2}), with typical grain sizes in the range 2--20 nm, have been synthesized by the condensation of ultrafine particles in a convective inert gas followed by their collection and in-situ consolidation in vacuum at ambient temperature. These new materials, owing to the reduced scale of their grains along with the enhanced cleanliness of their grain boundaries, are found to have significantly improved properties relative to those of their coarser-grained, conventionally-prepared counterparts. Nanophase rutile (TiO{sub 2}) with an initial mean grain diameter of 12 nm, for example, has been found to sintermore »« less
https://doi.org/10.1557/PROC-155-255

Full Text Available
Is superplasticity in the future of nanophase materials

Conference Siegel, R

The ultrafine grain sizes and high diffusivities in nanophase materials assembled from atomic clusters suggest that these materials may have a strong tendency toward superplastic mechanical behavior. Both small grain size and enhanced diffusivity can be expected to lead to increased diffusional creep rates as well as to a significantly greater propensity for grain boundary sliding. Recent mechanical properties measurements at room temperature on nanophase Cu, Pd, and TiO{sub 2}, however, give no indications of superplasticity. Nonetheless, significant ductility has been clearly demonstrated in these studies of both nanophase ceramics and metals. The synthesis of cluster-assembled nanophase materials is describedmore »« less
Full Text Available
Grain growth in nanocrystalline TiO sub 2 and its relation to vickers hardness and fracture toughness

Journal Article Hoefler, H; Averback, R - Scripta Metallurgica; (United States)

This paper reports on scientific interest in ultra-fine grained powders for processing of ceramic components motivated by the possibilities for the enhancement of sintering rates, reduction in flaw sizes and low-temperature superplastic deformation. Previous works have developed a technique, which combines the methods established of inert gas condensation of small particles and in situ powder compaction, for synthesizing materials with grain sizes {lt}10 nm. It has been shown that this method can be adapted for the production of ceramic nanocrystalline particles. Subsequent work has demonstrated that enhanced sintering and superplastic deformation is possible in nanocrystalline ceramics (TiO{sub 2}), but notmore »« less
Mechanical properties of nanophase TiO sub 2 as determined by nanoindentation

Journal Article Mayo, M; Siegel, R; Narayanasamy, A; ... - Journal of Materials Research; (USA)

Nanoindenter techniques have been used to determine the hardness, Young's modulus, and strain rate sensitivity of nanophase TiO{sub 2}, which is currently available only in very small quantities and which cannot be tested by most conventional techniques. Hardness and Young's modulus both increase linearly with sintering temperature over the range 25--900 {degree}C but come to within only 50--70% of the single crystal values. Strain rate sensitivity, on the other hand, is measurably greater for this material than for single crystal rutile, and the value of strain rate sensitivity increases as the grain size and the sintering temperature are decreased. Inmore »« less
https://doi.org/10.1557/JMR.1990.1073
Hot Superplastic Powder Forging for Transparent nanocrystalline Ceramics

Technical Report Cannon, W

The program explored a completely new, economical method of manufacturing nanocrystalline ceramics, Hot Superplastic Powder Forging (HSPF). The goal of the work was the development of nanocrystalline/low porosity optically transparent zirconia/alumina. The high optical transparency should result from lack of grain boundary scattering since grains will be smaller than one tenth the wavelength of light and from elimination of porosity. An important technological potential for this process is manufacturing of envelopes for high-pressure sodium vapor lamps. The technique for fabricating monolithic nanocrystalline material does not begin with powder whose particle diameter is <100 nm as is commonly done. Instead itmore »« less
https://doi.org/10.2172/890708

Full Text Available

Similar Records