Mechanical properties of silicon nitride-SiC platelet composites

Poorteman, Marc; Descamps, Philippe; Sakaguchi, Shuji; Cambier, F.; Gilbart, E.; Riley, F. L.; Brook, R. J.

doi:10.1016/0955-2219(91)90125-j

Cited by 11 publications

(4 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…19,20 Experimental results on the effect of SiC platelets on the mechanical properties of Si 3 N 4 composites are ambiguous. On the one hand, a slight increase in the fracture toughness (K Ic ) at ambient temperature was reported in some studies, 1,23,25 whereas no platelet-induced toughness change was observed by other authors. 24,26,28 On the other hand, many investigations unanimously reported drastic strength degradations in the presence of platelets; the room-temperature strength decreased to half that of the monolithic Si 3 N 4 matrix.…”

Section: Introductionmentioning

confidence: 90%

“…10 The intent of the second approach is to increase strength by incorporating second-phase ceramic reinforcing elements into the microstructure. Second-phase inclusions of various shapes have been tested in Si 3 N 4 , such as particles, 12 fibers, 13,14 whiskers, [15][16][17][18][19][20][21][22] and platelets, 1,[23][24][25][26][27][28][29] most of which were made of SiC. A beneficial effect of fibers and whiskers on the fracture toughness at ambient temperature was found in some cases; 14,15,21 however, in most of the investigations, no increase in strength or even a strength degradation was observed.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Silicon Nitride/Silicon Carbide Nanocomposite Materials: II, Hot Strength, Creep, and Oxidation Resistance

Rendtel

Hübner

Herrmann

et al. 1998

Journal of the American Ceramic Society

View full text Add to dashboard Cite

The mechanical properties of Si 3 N 4 /SiC nanocomposite materials that contained nanosized intercrystalline SiC dispersions that originated from different starting powders and were made via different fabrication routes were studied in the temperature range of 1400°-1550°C. The strength retained at 1400°C was between 70% and ∼100% of the room-temperature strength. Both creep and oxidation resistance were very high and were comparable to or better than those of the best Si 3 N 4 -based materials published previously. The effect of SiC particles on the creep properties can be understood in terms of a recent model of dilatational creep; however, the model invokes a series of microstructural, micromechanical, and chemical modifications.

show abstract

Section: Introductionmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Silicon Nitride/Silicon Carbide Nanocomposite Materials: II, Hot Strength, Creep, and Oxidation Resistance

Rendtel

Hübner

Herrmann

et al. 1998

Journal of the American Ceramic Society

View full text Add to dashboard Cite

show abstract

“…[55][56][57][58]67,167 This seems to suggest that the platelet morphology does not lend itself to the development of an interlocking network. Because the platelets are much stiffer than whiskers, they do not bend during hot pressing.…”

Section: Panel E: Dissolution-reprecipitation Creepmentioning

confidence: 99%

“…In contrast to the work with whiskers, creep measurements on ceramics reinforced with platelets have produced more modest results, with improvements of the creep resistance by up to 1 order of magnitude being observed. [55][56][57][58]67,167 This seems to suggest that the platelet morphology does not lend itself to the development of an interlocking network. Because the platelets are much stiffer than whiskers, they do not bend during hot pressing.…”

Section: Panel E: Dissolution-reprecipitation Creepmentioning

confidence: 99%

Creep Mechanisms in Multiphase Ceramic Materials

Wilkinson

1998

Journal of the American Ceramic Society

View full text Add to dashboard Cite

Hard, refractory particles long have been added to ceramic materials to impart creep resistance. The nature of such particles and the volume fraction added may vary widely between different systems. As a result, a rich variety of creep behavior and of attendant mechanisms is found. A critical survey is presented of the experimental data and of the models developed to rationalize them. Particular attention is paid to three materials systems: whisker-reinforced ceramics (e.g., SiC-whisker-reinforced Al 2 O 3 ); infiltrated powder compacts (e.g., siliconized SiC); and glass-bonded ceramics (e.g., sintered Si 3 N 4 ). A microstructural classification system is presented based on the nature of the network developed by the hard particles. This is useful as a guideline in developing mechanistic models. The current state of such models is reviewed critically. Although models for the high-and low-volume-fraction regions are well advanced, those applicable at intermediate volume fractions-relevant to whisker reinforcement for example-remain at an early stage. Finally, the experimental data on a range of materials are reviewed and classified. These data are compared with the models.

show abstract