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01872 Better ceramics through microwaves
12
RefrectoriWan7mEcs (properties, production, appkations) %I01 076 A comprehmslvr thermal ahock and fatigur mothodology for crramlcr In energy rpplicatlona Segall,A. E. et aL, Proc. 2nd Inr Con& Ceramics in Energy Applicadons,
12 REFRACTORIES/CERAMICS
The Indade 307-320.
Properties, Production, Applications 9WO1871 Aging of conmlcr undrr trmparatun gmdlont condltlons Vyshniauskas, V. Proc. 2nd Inr. Co& Ceramics in Energy Applicafions,
The Institute of Enera, 383384.
18 Devonshire St., London WIN UU,
1994,
Multicomponent oxide ceramics are used in high temperature constructions as a structural material and thermal insulator which simultaneously work under the influence of the severe thermal gradient and an a ssive cnvironment. Both the.se factors determine grain growth and Xee change in chemical composition of the preheated layers of material. The development of texture.under non-uniform temperature conditions are analysed. %I01872 Bettor caramicr through mlcrowavor Binner, J. G. and Cross, T. E. Proc. 2nd Int. Con. Ceramics in Ener
Applications, The Institute of Energy, 18 Devons / we St, London WYN 2Al.J 1994,33-42.
Microwave heating has been studied since the early 1950’s and is an cstablished process techni ue in the food and rubber industries. Over the past few years however, %ere has hecn an upsurge of interest in the possible application of microwave radiation as an altcrative energy source for the mo~~ssin~ of ceramic materials. This interest is associated both with the
of Energy, 18 Devonshire St., London WIN 2AlJ, 1994,
A comprehensive thermal shock and fatigue methodology was developed for ceramics used in indirect heating and heat-exchanger applications. The methodology employed a narrow circumferential helium quench to thermally shock and fatigue three commercially available silicon carbide tubes from 1ooo”C. Detailed transient temperature mcasumments required for thermal and stress calculations were obtained through the use of microthermocouples positioned along the internal surface of the tubes. Acoustic e.missions &y-used for in siru--_onitoeg of ,crack initiation and propaga~eno~th;~dent flaw populations durmg smgle and repeated (up to 10)
95101877 Doformation and fractun of conmIca for onrrgy rpplIcatlon8 Gogotsi, G. A. and Ostrovoy,D. Y. Proc. 2nd Int. Confr Ceramics in Energy Applications, The Institute of Energy, 18 Devonshire St., London WIN 2AU, 1994, 369,779. The authom carried out investigation on silicon nitride, alumina and x&co-
nia ceramics as well as xirconia single crystals.
95101878 Dovolopmont of thlrd-gonoratlon rpark-plrsmr-rlnWing (SPS) ryotoms. Advanced production procou for flnr uramlcr and functionally gmdlrnt matrrlrlr Tokita, M. Nyu Seramikkusy 1994, 7, Q, 63-74. (In Japanese)
some of the processing options being investigated and will focus on areas where improvements in properties have been achieved or are being sought. An attempt will be made to look into the future and predict the potential for this processing option. 9WO1873 Ceramic flltarr for hot gas dorulfurlzatlon. Part II Uccker, D. C. et al., Brennst.-Waerme-Krafi, 1994, 46, (S), X33-237. (In German) Coal gas scrubbing for removal of H,S at f approximately 520”and ~20 bar was discussed. Ceramic filters for the desulphurixation were developed based on ceramic sponges prepared by calcination of polyurethane foams that had been soaked in precursor clay suspensions. %I01 074
Coating method for Innovative gmphltlc compo nents wlth hlgh corrosion nrlstanu Hurtado, A. M. et al., Roe. 2nd Int. Conf. Ceramics in Energy A plica-
tions, The Institute of Energy, 18 Devonshire St., London WlN 24 J ,1994, 65-77.
The main intention of ceramic coatings for graphitic structures in energy applications is to realize corrosion and wear resistance in the temperature range helween 450 and 1600°C. Different graphite qualities were tested to obtain a wide basis for producing these coated strucIures. At the Technical University of &&en a special coating method was successfully developed for the above mentioned aim. To characterixe the produced coatin of tests were carried out in the temperature range fmm 500 to 15OO%.az: gravimetrically measured reaction rates in air at velocities of approximate1 0.1 m/s amount to R-z1 m cm’h. Thermal shock tests also showed that d cse ceramic coatings are I*feally suited to protect graphitic compo nents in corrosive media.
95/01875 Comparatlvo study of tart mathodologlos for thormal @hockand thormal fatlgm katlng of coramlcs In high tom paratun enorgy appllcrtlonr Jickells, A. J. et aL, Proc. 2nd Int. Confr Ceramics in Energy Applica-
tions, The Institute of Energy 18 Devonshire St., London WIN UU, 1994, 253-272.
Various thermal cycles operate within gas fired indireU heating systems, ranging from high thermal difference-low cycle frequency (start u ) to low thermal difference-hi cycle frequency (temperature mor!ulation). Ceramic materials use8 m such systems are required to perform satisfactorily when subject to such operating environments. A stud to corn are and *I! as been contrast three thermal shock and thermal fatigue meth ocrologles carried out in specialist test facilities, independently developed by the three partners lo simulate these conditions. The test methods evaluated the degradation of ceramic properties via MOR bars, disks and tubular specimens. Three commercial silicon carbide materials, which are used for ceramic radiant tubes, were evaluated in the programme.
128
Fuel and Enorgy Abstracts March 1995
Discusses the outline and principle of spark-plasma-sintering method and applications of the SPS method to the processing of ceramic materials.
Evaluation of thormrl rhock and thormal ndr%I01 879 tanca of thtw nrctlon bonded rlllcon carbldo conmica Alliat, I. and Petit. N. Proc. 2nd Ink Conf Ceramics in Energy Applications. The Institute of Enerpv. -. 18 Devonshire St.. London WlN 2AU. 1994. 291 -jO5.
Natural gas-fired heating devices in industrial application are desi vzz withstand high temperatures and surrounding thermal variations. A#F ceramics are used because they have a thermal resistance and a chemical inertia hieher than those of metals. However. thcv are brittle materials. sensitive to sudden heating or cooling. Thus their &ermai shock and the& mal fatigue behaviours are prime factors in determining the reliability and durabilic of devices. A sp&ial testing method is req&ed to chara~crixe structural ceramics with a view to their future uses. In this paper the authors present the various stages of methodology lo characterize the thermal shock and thermal fatigue strengths applied to test specimens in the case of quick cooling by air. Reports on the experimental results obtained with three similar commercial technical ceramics.
Fractun mochmlcal chrract~rizatlon of thormal damaga of coramlcs by munr of lrwr Irmdlatlon
95lOl880
Kidhoff, G. et al., Proc. 2nd Int, Conf: Ceramics in Enera Applications, The Ins&ute of- Eneray - 18 Devonshire St.. London WIN 2AU. 1994, 3392351.
By suitably scanning a circular sample with a beam from a 1 kW-Nd-YAG laser, steep tcmpemlture gradients and high stresses can be generated. Ceramics with outstandinn hieh temoerature strennth have been tested. such as silicon nitride. ‘l&ma shock figures-of&i~ have been calcu~ lated from the measured temperature field at the instant of fmcture. By means of repeated thermal loading, the number of cycles to failure and the parameter of subcritical crack growth have been detemdncd for unnotched samples. In addition to elastic effecta, damage due to tensile stresses arising after stress relaxation by creep has been demonstrated.
High tompomtum propertior of HPSN under load In %lOl%l rlmulatod coal garlficatlon ?? nvlronmanta Hoffmann, M. et aL, Proc. 2nd Int. Con& Ceramics in Energy Applica-
tions, The Institute of Energy, 18 Devonshire St, London WIN 2AU. 1994. 225-237.
In this paper the influence of a simulated coal gasification environment on the mechanical properties of a commercial hot pressed silicon nitride is investigated.
RefrectoriWan7mEcs (properties, production, appkations) %I01 076 A comprehmslvr thermal ahock and fatigur mothodology for crramlcr In energy rpplicatlona Segall,A. E. et aL, Proc. 2nd Inr Con& Ceramics in Energy Applicadons,
12 REFRACTORIES/CERAMICS
The Indade 307-320.
Properties, Production, Applications 9WO1871 Aging of conmlcr undrr trmparatun gmdlont condltlons Vyshniauskas, V. Proc. 2nd Inr. Co& Ceramics in Energy Applicafions,
The Institute of Enera, 383384.
18 Devonshire St., London WIN UU,
1994,
Multicomponent oxide ceramics are used in high temperature constructions as a structural material and thermal insulator which simultaneously work under the influence of the severe thermal gradient and an a ssive cnvironment. Both the.se factors determine grain growth and Xee change in chemical composition of the preheated layers of material. The development of texture.under non-uniform temperature conditions are analysed. %I01872 Bettor caramicr through mlcrowavor Binner, J. G. and Cross, T. E. Proc. 2nd Int. Con. Ceramics in Ener
Applications, The Institute of Energy, 18 Devons / we St, London WYN 2Al.J 1994,33-42.
Microwave heating has been studied since the early 1950’s and is an cstablished process techni ue in the food and rubber industries. Over the past few years however, %ere has hecn an upsurge of interest in the possible application of microwave radiation as an altcrative energy source for the mo~~ssin~ of ceramic materials. This interest is associated both with the
of Energy, 18 Devonshire St., London WIN 2AlJ, 1994,
A comprehensive thermal shock and fatigue methodology was developed for ceramics used in indirect heating and heat-exchanger applications. The methodology employed a narrow circumferential helium quench to thermally shock and fatigue three commercially available silicon carbide tubes from 1ooo”C. Detailed transient temperature mcasumments required for thermal and stress calculations were obtained through the use of microthermocouples positioned along the internal surface of the tubes. Acoustic e.missions &y-used for in siru--_onitoeg of ,crack initiation and propaga~eno~th;~dent flaw populations durmg smgle and repeated (up to 10)
95101877 Doformation and fractun of conmIca for onrrgy rpplIcatlon8 Gogotsi, G. A. and Ostrovoy,D. Y. Proc. 2nd Int. Confr Ceramics in Energy Applications, The Institute of Energy, 18 Devonshire St., London WIN 2AU, 1994, 369,779. The authom carried out investigation on silicon nitride, alumina and x&co-
nia ceramics as well as xirconia single crystals.
95101878 Dovolopmont of thlrd-gonoratlon rpark-plrsmr-rlnWing (SPS) ryotoms. Advanced production procou for flnr uramlcr and functionally gmdlrnt matrrlrlr Tokita, M. Nyu Seramikkusy 1994, 7, Q, 63-74. (In Japanese)
some of the processing options being investigated and will focus on areas where improvements in properties have been achieved or are being sought. An attempt will be made to look into the future and predict the potential for this processing option. 9WO1873 Ceramic flltarr for hot gas dorulfurlzatlon. Part II Uccker, D. C. et al., Brennst.-Waerme-Krafi, 1994, 46, (S), X33-237. (In German) Coal gas scrubbing for removal of H,S at f approximately 520”and ~20 bar was discussed. Ceramic filters for the desulphurixation were developed based on ceramic sponges prepared by calcination of polyurethane foams that had been soaked in precursor clay suspensions. %I01 074
Coating method for Innovative gmphltlc compo nents wlth hlgh corrosion nrlstanu Hurtado, A. M. et al., Roe. 2nd Int. Conf. Ceramics in Energy A plica-
tions, The Institute of Energy, 18 Devonshire St., London WlN 24 J ,1994, 65-77.
The main intention of ceramic coatings for graphitic structures in energy applications is to realize corrosion and wear resistance in the temperature range helween 450 and 1600°C. Different graphite qualities were tested to obtain a wide basis for producing these coated strucIures. At the Technical University of &&en a special coating method was successfully developed for the above mentioned aim. To characterixe the produced coatin of tests were carried out in the temperature range fmm 500 to 15OO%.az: gravimetrically measured reaction rates in air at velocities of approximate1 0.1 m/s amount to R-z1 m cm’h. Thermal shock tests also showed that d cse ceramic coatings are I*feally suited to protect graphitic compo nents in corrosive media.
95/01875 Comparatlvo study of tart mathodologlos for thormal @hockand thormal fatlgm katlng of coramlcs In high tom paratun enorgy appllcrtlonr Jickells, A. J. et aL, Proc. 2nd Int. Confr Ceramics in Energy Applica-
tions, The Institute of Energy 18 Devonshire St., London WIN UU, 1994, 253-272.
Various thermal cycles operate within gas fired indireU heating systems, ranging from high thermal difference-low cycle frequency (start u ) to low thermal difference-hi cycle frequency (temperature mor!ulation). Ceramic materials use8 m such systems are required to perform satisfactorily when subject to such operating environments. A stud to corn are and *I! as been contrast three thermal shock and thermal fatigue meth ocrologles carried out in specialist test facilities, independently developed by the three partners lo simulate these conditions. The test methods evaluated the degradation of ceramic properties via MOR bars, disks and tubular specimens. Three commercial silicon carbide materials, which are used for ceramic radiant tubes, were evaluated in the programme.
128
Fuel and Enorgy Abstracts March 1995
Discusses the outline and principle of spark-plasma-sintering method and applications of the SPS method to the processing of ceramic materials.
Evaluation of thormrl rhock and thormal ndr%I01 879 tanca of thtw nrctlon bonded rlllcon carbldo conmica Alliat, I. and Petit. N. Proc. 2nd Ink Conf Ceramics in Energy Applications. The Institute of Enerpv. -. 18 Devonshire St.. London WlN 2AU. 1994. 291 -jO5.
Natural gas-fired heating devices in industrial application are desi vzz withstand high temperatures and surrounding thermal variations. A#F ceramics are used because they have a thermal resistance and a chemical inertia hieher than those of metals. However. thcv are brittle materials. sensitive to sudden heating or cooling. Thus their &ermai shock and the& mal fatigue behaviours are prime factors in determining the reliability and durabilic of devices. A sp&ial testing method is req&ed to chara~crixe structural ceramics with a view to their future uses. In this paper the authors present the various stages of methodology lo characterize the thermal shock and thermal fatigue strengths applied to test specimens in the case of quick cooling by air. Reports on the experimental results obtained with three similar commercial technical ceramics.
Fractun mochmlcal chrract~rizatlon of thormal damaga of coramlcs by munr of lrwr Irmdlatlon
95lOl880
Kidhoff, G. et al., Proc. 2nd Int, Conf: Ceramics in Enera Applications, The Ins&ute of- Eneray - 18 Devonshire St.. London WIN 2AU. 1994, 3392351.
By suitably scanning a circular sample with a beam from a 1 kW-Nd-YAG laser, steep tcmpemlture gradients and high stresses can be generated. Ceramics with outstandinn hieh temoerature strennth have been tested. such as silicon nitride. ‘l&ma shock figures-of&i~ have been calcu~ lated from the measured temperature field at the instant of fmcture. By means of repeated thermal loading, the number of cycles to failure and the parameter of subcritical crack growth have been detemdncd for unnotched samples. In addition to elastic effecta, damage due to tensile stresses arising after stress relaxation by creep has been demonstrated.
High tompomtum propertior of HPSN under load In %lOl%l rlmulatod coal garlficatlon ?? nvlronmanta Hoffmann, M. et aL, Proc. 2nd Int. Con& Ceramics in Energy Applica-
tions, The Institute of Energy, 18 Devonshire St, London WIN 2AU. 1994. 225-237.
In this paper the influence of a simulated coal gasification environment on the mechanical properties of a commercial hot pressed silicon nitride is investigated.