Analysis of the intragranular microstructure in ceramic nanocomposites and their effect on the mechanical properties

Abstract

The formation of intragranular microstructure in Al2O3/ZrO2 and Si2N2O/Si3N4 nanocomposites was analyzed, and the effect of intragranular microstructure on the mechanical properties of nanocomposites was investigated. Results suggest 3 requisite conditions for the formation of intragranular microstructure and the role of intracrystalline glass phase and scar microstructure. In case of Al2O3/ZrO2, the intragranular microstructure leads to the formation of transgranular fracture, which in turn improves the mechanical properties via strengthening and toughening. On the other hand, in case of Si3N4/Si2N2O nanocomposites, intragranular microstructure reduces the possibility of bridging, pulling out, and crack deflection, thereby leading to the deterioration of strength and toughness. Based on these results, we can conclude that the formation of intragranular microstructure does not necessarily improve the mechanical properties in all kinds of materials. Rather, the effect of intragranular microstructure on the mechanical properties of nanocomposites is related to the strengthening and toughing mechanism of matrix materials.

Effect of micron aluminium powder on mechanical properties and microstructural in zirconia toughened alumina ceramics

“…Luo et al . [16] and Chen et al . [18] obtained a similar conclusion that abnormal growth of Al 2 O 3 and normal growth of ZrO 2 leads to the formed of intragranular ZrO 2 .…”

“…Intragranular ZrO 2 increases the strength of the main grain boundaries around but decreases the strength of matrix grain by producing a large number of sub‐grain boundaries and micro‐cracks. As a result, the fracture mode has been transformed from intergranular fracture to transgranular fracture, to improve the comprehensive mechanical properties of ZTA ceramics [16].…”

“…Two major kinds of methods have been reported. Firstly, the sintering process facilitates the grain growth of Al 2 O 3 so that the matrix swallows up ZrO 2 particles [16–18]. However, this method has a lot of influence factors to control, such as sintering method, sintering temperature, sintering time, and doping Si and Ca etc.…”

Electrical discharge machining of ceramic nanocomposites: sublimation phenomena and adaptive control

“…The excellent properties of ceramics such as high hardness, resistance to abrasion, erosion, and corrosion, absence of chemical interaction in the working medium and with the environment, and low thermal expansion make them unreplaceable for the aviation and aerospace industry and in other important applications [33, 34, 35, 36, 37, 38, 39, 40]. In medicine, ceramic implants show their reliability, high wear resistance, absence of metal ion accumulation, reduced risk of revision surgery, and negative consequences [41, 42, 43].…”

Preparation and heat-insulating properties of Al2O3–ZrO2(Y2O3) hollow fibers derived from cogon using an orthogonal experimental design

“…5 Herein, it is, in principle, feasible to develop novel lightweight refractories by synthesizing Al 2 O 3 -ZrO 2 composites. [13][14][15][16][17] Using solution blow spinning and atomic layer deposition (ALD), Xu et al produced novel Al 2 O 3 nanotube aerogels having a pore size of 1-2 mm, whose thermal conductivity is only 0.022 W m À1 K À1 at room temperature. 7 Nevertheless, few studies have reported the thermal performance of Al 2 O 3 -ZrO 2 composites at a high temperature (900-1600 C) till now.…”