The strength of Al2O3/SiC nanocomposites after grinding and annealing

Wu, Houzheng; Lawrence, Charles Wilson; Roberts, Steve; Derby, Brian

doi:10.1016/s1359-6454(98)00068-8

Cited by 86 publications

(48 citation statements)

References 18 publications

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“…4 with different volume fractions of SiC nanoparticles, where the following data reported recently by Sun et al [26] are used: It should be pointed out that while the above analysis exhibits a fairly good agreement with the experimental results reported in the literature [9][10][11]24,26], the dislocation activities in the CMNCs are different from those in the precipitation-hardened metallic materials. For example, unlike aluminum alloys and nickel-based sueralloys, the dislocations in ceramics can hardly move on the slip plane and be stopped by the barrier to form the conventional Orowan loops at room temperature.…”

Section: Verification and Discussionsupporting

confidence: 69%

“…2. A comparison of the model prediction with the experimental data for SiC particulate-reinforced alumina nanocomposites tested at room temperature, where the error bars were based on the range given in Refs. [10,11]. monolithic alumina, and the value of K IC increases with decrease in size of SiC nanoparticles as well.…”

Section: Verification and Discussionmentioning

confidence: 95%

“…Fig. 2 shows another comparison, where the following data for Al 2 O 3 /SiC p nanocomposites reported by Wu et al [10,11] are used: s fm ¼ 295 MPa [10,11], T process ¼ 1650 1C, T test ¼ 20 1C, d p ¼ 90 nm, and other parameters remain the same as given above. It appears reasonable that the experimental result could be lower than the model prediction after annealing, since all the dislocations were assumed to punch out and disperse into the matrix to enhance the strength, as indicated by Eq.…”

Section: Verification and Discussionmentioning

confidence: 99%

“…3 shows a comparison between the experimental data and model prediction with different nanoparticle sizes. The following data given by Wu et al [10] and Carroll et al [24] are used: Experimental data (before annealing)…”

Section: Verification and Discussionmentioning

confidence: 99%

“…Nano-sized particles present within matrix grains strengthen the grain boundaries due to compressive radial stresses, where the alumina matrix has a larger thermal expansion coefficient than that of silicon carbide particles [5,8]. Others include flaw-healing mechanisms [9,10].…”

Section: Dislocations In Cmncsmentioning

confidence: 99%

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Prediction of fracture strength in Al₂O₃/SiC_pceramic matrix nanocomposites

Zhang

Chen²

2007

Science and Technology of Advanced Materials

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Based primarily on a recent publication [S.M. Choi, H. Awaji, Sci. Tech. Adv. Mater. 6 (2005) 2-10.], where the dislocations around the nano-sized particles in the intra-granular type of ceramic matrix nanocomposites (CMNCs) were modeled, dislocation activities in Al 2 O 3 /SiC p CMNCs were discussed in relation to the processing conditions. The dislocations around the nano-sized particles, caused by the thermal mismatch between the ceramic matrix and nano-sized particles, were assumed to hold out the effect of Orowan-like strengthening, although the conventional Owowan loops induced by the movement of dislocations were unlikely in the ceramic matrix at room temperature. A model involving the yield strength of metal matrix nanocomposites (MMNCs), where the Owowan strengthening effect was taken into consideration, was thus modified and extended to predict the fracture strength of the intra-granular type of CMNCs without and with annealing. On the basis of the characteristics of dislocations in the CMNCs, the load-bearing effect and Orowan-like strengthening were considered before annealing, while the load-bearing effect and enhanced dislocation density strengthening were taken into account after annealing. The model prediction was found to be in agreement with the experimental data of Al 2 O 3 /SiC p nanocomposites reported in the literature. r

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