Hot-pressing and the α-β phase transformation in silicon nitride
Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enh...
Ausführliche Beschreibung
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| Autor*in: |
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| Format: |
E-Artikel |
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| Sprache: |
Englisch |
| Erschienen: |
1978 |
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| Umfang: |
10 |
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| Reproduktion: |
Springer Online Journal Archives 1860-2002 |
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| Übergeordnetes Werk: |
in: Journal of materials science - 1966, 13(1978) vom: Feb., Seite 341-350 |
| Übergeordnetes Werk: |
volume:13 ; year:1978 ; month:02 ; pages:341-350 ; extent:10 |
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NLEJ194544109 |
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| 520 | |a Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enhanced above 1550° C, which operates up to relative densities of about 0.65. The kinetics of the much slower decelerating second stage obey the Coble hot-pressing equation and the rate of densification is found to be proportional to the amount of additive. The controlling mechanism is believed to be diffusion in a boundary second phase, and values for the diffusion coefficient,D b, of the rate-controlling species in the boundary phase for temperatures above and below 1550° C are given. The kinetics of theα toβ transformation, the greater part of which occurs after densification is complete, are described by a first order reaction; the dependence of rate on the quantity of additive and on temperature is similar to that found for densification, and a similar controlling mechanism is believed to be responsible for the two processes. | ||
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| 700 | 1 | |a Brook, R. J. |4 oth | |
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(DE-627)NLEJ194544109 DE-627 ger DE-627 rakwb eng Hot-pressing and the α-β phase transformation in silicon nitride 1978 10 nicht spezifiziert zzz rdacontent nicht spezifiziert z rdamedia nicht spezifiziert zu rdacarrier Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enhanced above 1550° C, which operates up to relative densities of about 0.65. The kinetics of the much slower decelerating second stage obey the Coble hot-pressing equation and the rate of densification is found to be proportional to the amount of additive. The controlling mechanism is believed to be diffusion in a boundary second phase, and values for the diffusion coefficient,D b, of the rate-controlling species in the boundary phase for temperatures above and below 1550° C are given. The kinetics of theα toβ transformation, the greater part of which occurs after densification is complete, are described by a first order reaction; the dependence of rate on the quantity of additive and on temperature is similar to that found for densification, and a similar controlling mechanism is believed to be responsible for the two processes. Springer Online Journal Archives 1860-2002 Bowen, L. J. oth Weston, R. J. oth Carruthers, T. G. oth Brook, R. J. oth in Journal of materials science 1966 13(1978) vom: Feb., Seite 341-350 (DE-627)NLEJ188987134 (DE-600)2015305-3 1573-4803 nnns volume:13 year:1978 month:02 pages:341-350 extent:10 http://dx.doi.org/10.1007/BF00647779 GBV_USEFLAG_U ZDB-1-SOJ GBV_NL_ARTICLE AR 13 1978 2 341-350 10 |
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(DE-627)NLEJ194544109 DE-627 ger DE-627 rakwb eng Hot-pressing and the α-β phase transformation in silicon nitride 1978 10 nicht spezifiziert zzz rdacontent nicht spezifiziert z rdamedia nicht spezifiziert zu rdacarrier Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enhanced above 1550° C, which operates up to relative densities of about 0.65. The kinetics of the much slower decelerating second stage obey the Coble hot-pressing equation and the rate of densification is found to be proportional to the amount of additive. The controlling mechanism is believed to be diffusion in a boundary second phase, and values for the diffusion coefficient,D b, of the rate-controlling species in the boundary phase for temperatures above and below 1550° C are given. The kinetics of theα toβ transformation, the greater part of which occurs after densification is complete, are described by a first order reaction; the dependence of rate on the quantity of additive and on temperature is similar to that found for densification, and a similar controlling mechanism is believed to be responsible for the two processes. Springer Online Journal Archives 1860-2002 Bowen, L. J. oth Weston, R. J. oth Carruthers, T. G. oth Brook, R. J. oth in Journal of materials science 1966 13(1978) vom: Feb., Seite 341-350 (DE-627)NLEJ188987134 (DE-600)2015305-3 1573-4803 nnns volume:13 year:1978 month:02 pages:341-350 extent:10 http://dx.doi.org/10.1007/BF00647779 GBV_USEFLAG_U ZDB-1-SOJ GBV_NL_ARTICLE AR 13 1978 2 341-350 10 |
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(DE-627)NLEJ194544109 DE-627 ger DE-627 rakwb eng Hot-pressing and the α-β phase transformation in silicon nitride 1978 10 nicht spezifiziert zzz rdacontent nicht spezifiziert z rdamedia nicht spezifiziert zu rdacarrier Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enhanced above 1550° C, which operates up to relative densities of about 0.65. The kinetics of the much slower decelerating second stage obey the Coble hot-pressing equation and the rate of densification is found to be proportional to the amount of additive. The controlling mechanism is believed to be diffusion in a boundary second phase, and values for the diffusion coefficient,D b, of the rate-controlling species in the boundary phase for temperatures above and below 1550° C are given. The kinetics of theα toβ transformation, the greater part of which occurs after densification is complete, are described by a first order reaction; the dependence of rate on the quantity of additive and on temperature is similar to that found for densification, and a similar controlling mechanism is believed to be responsible for the two processes. Springer Online Journal Archives 1860-2002 Bowen, L. J. oth Weston, R. J. oth Carruthers, T. G. oth Brook, R. J. oth in Journal of materials science 1966 13(1978) vom: Feb., Seite 341-350 (DE-627)NLEJ188987134 (DE-600)2015305-3 1573-4803 nnns volume:13 year:1978 month:02 pages:341-350 extent:10 http://dx.doi.org/10.1007/BF00647779 GBV_USEFLAG_U ZDB-1-SOJ GBV_NL_ARTICLE AR 13 1978 2 341-350 10 |
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(DE-627)NLEJ194544109 DE-627 ger DE-627 rakwb eng Hot-pressing and the α-β phase transformation in silicon nitride 1978 10 nicht spezifiziert zzz rdacontent nicht spezifiziert z rdamedia nicht spezifiziert zu rdacarrier Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enhanced above 1550° C, which operates up to relative densities of about 0.65. The kinetics of the much slower decelerating second stage obey the Coble hot-pressing equation and the rate of densification is found to be proportional to the amount of additive. The controlling mechanism is believed to be diffusion in a boundary second phase, and values for the diffusion coefficient,D b, of the rate-controlling species in the boundary phase for temperatures above and below 1550° C are given. The kinetics of theα toβ transformation, the greater part of which occurs after densification is complete, are described by a first order reaction; the dependence of rate on the quantity of additive and on temperature is similar to that found for densification, and a similar controlling mechanism is believed to be responsible for the two processes. Springer Online Journal Archives 1860-2002 Bowen, L. J. oth Weston, R. J. oth Carruthers, T. G. oth Brook, R. J. oth in Journal of materials science 1966 13(1978) vom: Feb., Seite 341-350 (DE-627)NLEJ188987134 (DE-600)2015305-3 1573-4803 nnns volume:13 year:1978 month:02 pages:341-350 extent:10 http://dx.doi.org/10.1007/BF00647779 GBV_USEFLAG_U ZDB-1-SOJ GBV_NL_ARTICLE AR 13 1978 2 341-350 10 |
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(DE-627)NLEJ194544109 DE-627 ger DE-627 rakwb eng Hot-pressing and the α-β phase transformation in silicon nitride 1978 10 nicht spezifiziert zzz rdacontent nicht spezifiziert z rdamedia nicht spezifiziert zu rdacarrier Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enhanced above 1550° C, which operates up to relative densities of about 0.65. The kinetics of the much slower decelerating second stage obey the Coble hot-pressing equation and the rate of densification is found to be proportional to the amount of additive. The controlling mechanism is believed to be diffusion in a boundary second phase, and values for the diffusion coefficient,D b, of the rate-controlling species in the boundary phase for temperatures above and below 1550° C are given. The kinetics of theα toβ transformation, the greater part of which occurs after densification is complete, are described by a first order reaction; the dependence of rate on the quantity of additive and on temperature is similar to that found for densification, and a similar controlling mechanism is believed to be responsible for the two processes. Springer Online Journal Archives 1860-2002 Bowen, L. J. oth Weston, R. J. oth Carruthers, T. G. oth Brook, R. J. oth in Journal of materials science 1966 13(1978) vom: Feb., Seite 341-350 (DE-627)NLEJ188987134 (DE-600)2015305-3 1573-4803 nnns volume:13 year:1978 month:02 pages:341-350 extent:10 http://dx.doi.org/10.1007/BF00647779 GBV_USEFLAG_U ZDB-1-SOJ GBV_NL_ARTICLE AR 13 1978 2 341-350 10 |
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Hot-pressing and the α-β phase transformation in silicon nitride |
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Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enhanced above 1550° C, which operates up to relative densities of about 0.65. The kinetics of the much slower decelerating second stage obey the Coble hot-pressing equation and the rate of densification is found to be proportional to the amount of additive. The controlling mechanism is believed to be diffusion in a boundary second phase, and values for the diffusion coefficient,D b, of the rate-controlling species in the boundary phase for temperatures above and below 1550° C are given. The kinetics of theα toβ transformation, the greater part of which occurs after densification is complete, are described by a first order reaction; the dependence of rate on the quantity of additive and on temperature is similar to that found for densification, and a similar controlling mechanism is believed to be responsible for the two processes. |
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Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enhanced above 1550° C, which operates up to relative densities of about 0.65. The kinetics of the much slower decelerating second stage obey the Coble hot-pressing equation and the rate of densification is found to be proportional to the amount of additive. The controlling mechanism is believed to be diffusion in a boundary second phase, and values for the diffusion coefficient,D b, of the rate-controlling species in the boundary phase for temperatures above and below 1550° C are given. The kinetics of theα toβ transformation, the greater part of which occurs after densification is complete, are described by a first order reaction; the dependence of rate on the quantity of additive and on temperature is similar to that found for densification, and a similar controlling mechanism is believed to be responsible for the two processes. |
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Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enhanced above 1550° C, which operates up to relative densities of about 0.65. The kinetics of the much slower decelerating second stage obey the Coble hot-pressing equation and the rate of densification is found to be proportional to the amount of additive. The controlling mechanism is believed to be diffusion in a boundary second phase, and values for the diffusion coefficient,D b, of the rate-controlling species in the boundary phase for temperatures above and below 1550° C are given. The kinetics of theα toβ transformation, the greater part of which occurs after densification is complete, are described by a first order reaction; the dependence of rate on the quantity of additive and on temperature is similar to that found for densification, and a similar controlling mechanism is believed to be responsible for the two processes. |
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<?xml version="1.0" encoding="UTF-8"?><collection xmlns="http://www.loc.gov/MARC21/slim"><record><leader>01000caa a22002652 4500</leader><controlfield tag="001">NLEJ194544109</controlfield><controlfield tag="003">DE-627</controlfield><controlfield tag="005">20210707232246.0</controlfield><controlfield tag="007">cr uuu---uuuuu</controlfield><controlfield tag="008">070526s1978 xx |||||o 00| ||eng c</controlfield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(DE-627)NLEJ194544109</subfield></datafield><datafield tag="040" ind1=" " ind2=" "><subfield code="a">DE-627</subfield><subfield code="b">ger</subfield><subfield code="c">DE-627</subfield><subfield code="e">rakwb</subfield></datafield><datafield tag="041" ind1=" " ind2=" "><subfield code="a">eng</subfield></datafield><datafield tag="245" ind1="1" ind2="0"><subfield code="a">Hot-pressing and the α-β phase transformation in silicon nitride</subfield></datafield><datafield tag="264" ind1=" " ind2="1"><subfield code="c">1978</subfield></datafield><datafield tag="300" ind1=" " ind2=" "><subfield code="a">10</subfield></datafield><datafield tag="336" ind1=" " ind2=" "><subfield code="a">nicht spezifiziert</subfield><subfield code="b">zzz</subfield><subfield code="2">rdacontent</subfield></datafield><datafield tag="337" ind1=" " ind2=" "><subfield code="a">nicht spezifiziert</subfield><subfield code="b">z</subfield><subfield code="2">rdamedia</subfield></datafield><datafield tag="338" ind1=" " ind2=" "><subfield code="a">nicht spezifiziert</subfield><subfield code="b">zu</subfield><subfield code="2">rdacarrier</subfield></datafield><datafield tag="520" ind1=" " ind2=" "><subfield code="a">Abstract The kinetics of densification and the kinetics of theα-β phase transformation have been measured during the hot-pressing of silicon nitride ceramics using magnesia as additive. Two mechanisms of densification have been identified. The first is a very rapid particle rearrangement, liquid-enhanced above 1550° C, which operates up to relative densities of about 0.65. The kinetics of the much slower decelerating second stage obey the Coble hot-pressing equation and the rate of densification is found to be proportional to the amount of additive. The controlling mechanism is believed to be diffusion in a boundary second phase, and values for the diffusion coefficient,D b, of the rate-controlling species in the boundary phase for temperatures above and below 1550° C are given. The kinetics of theα toβ transformation, the greater part of which occurs after densification is complete, are described by a first order reaction; the dependence of rate on the quantity of additive and on temperature is similar to that found for densification, and a similar controlling mechanism is believed to be responsible for the two processes.</subfield></datafield><datafield tag="533" ind1=" " ind2=" "><subfield code="f">Springer Online Journal Archives 1860-2002</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Bowen, L. J.</subfield><subfield code="4">oth</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Weston, R. J.</subfield><subfield code="4">oth</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Carruthers, T. G.</subfield><subfield code="4">oth</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Brook, R. J.</subfield><subfield code="4">oth</subfield></datafield><datafield tag="773" ind1="0" ind2="8"><subfield code="i">in</subfield><subfield code="t">Journal of materials science</subfield><subfield code="d">1966</subfield><subfield code="g">13(1978) vom: Feb., Seite 341-350</subfield><subfield code="w">(DE-627)NLEJ188987134</subfield><subfield code="w">(DE-600)2015305-3</subfield><subfield code="x">1573-4803</subfield><subfield code="7">nnns</subfield></datafield><datafield tag="773" ind1="1" ind2="8"><subfield code="g">volume:13</subfield><subfield code="g">year:1978</subfield><subfield code="g">month:02</subfield><subfield code="g">pages:341-350</subfield><subfield code="g">extent:10</subfield></datafield><datafield tag="856" ind1="4" ind2="0"><subfield code="u">http://dx.doi.org/10.1007/BF00647779</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">GBV_USEFLAG_U</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">ZDB-1-SOJ</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">GBV_NL_ARTICLE</subfield></datafield><datafield tag="951" ind1=" " ind2=" "><subfield code="a">AR</subfield></datafield><datafield tag="952" ind1=" " ind2=" "><subfield code="d">13</subfield><subfield code="j">1978</subfield><subfield code="c">2</subfield><subfield code="h">341-350</subfield><subfield code="g">10</subfield></datafield></record></collection>
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7.3981237 |