Tensile Fracture Behavior and Characterization of Ceramic Matrix Composites

Abstract

Tensile fracture behavior of ceramic matrix composites (CMCs) was investigated using characterization tools. First, a high-speed infrared camera was used to monitor the surface temperature of the CMC specimen during mechanical testing. An infrared camera is a tool used to detect infrared (IR) radiation emitted from a specimen as a function of temperature, and it was used to analyze the temperature monitoring of specimen surface and fracture behavior during the tensile test. After the test, the microstructural analysis using SEM was performed. SEM analysis was performed to investigate the fracture mode and fracture mechanism of CMC materials. In this paper, it was found that the results of the surface temperature monitoring obtained from IR thermal imaging technology and the failure mode analysis obtained through SEM were in a good agreement. These techniques were useful tools to explain the mechanical behavior of ceramic matrix composites. The detailed experiments and testing results will be provided.

Investigation of Failure Mechanisms in Ceramic Composites as Potential Railway Brake Disc Materials

“…Nicalon/SiC composites are representative ceramic composites that are used in various applications such as ceramic rotors and heat exchangers, etc. [ 1 , 2 , 3 , 4 ]. These composites can be used as friction materials in the future railway field, therefore, they were applied in this study.…”

“…Ceramic composites are structural materials used at high temperatures that have been proven over the past few decades [ 1 , 2 , 3 , 4 ]. For this reason, it has been spotlighted as an excellent material in spacecraft insulation materials, high-temperature gas turbine rotors, and thermal management systems, and, recently, it is expanding its use as a material for brake discs for automobiles and railways [ 1 , 2 , 3 , 4 , 5 , 6 ]. Stadler et al studied ceramic composite materials as friction materials [ 7 ].…”

“…In general, monolithic ceramics exhibit excellent high-temperature properties, corrosion resistance, abrasion resistance, etc., but their use is limited due to the essential characteristics of brittleness. Therefore, the development of a technology that imparts toughness to such monolithic ceramics has become important, and one solution to this is ceramic composite materials reinforced with ceramic fibers [ 1 , 2 , 3 , 4 , 5 , 10 , 11 ].…”

“…On the other hand, in the case of the ceramic composite material reinforced with continuous fibers, it initially shows the elastic behavior of monolithic ceramics, and then shows the first matrix cracking as the load applied to the specimen increases. However, as the stress increases, the continuous increase in load continues due to complex interactions such as further matrix failure due to fibers present inside the matrix and crack deflection at the interface between the fibers and the matrix ( Figure 1 ) [ 3 , 4 , 10 , 11 , 12 ]. After the ultimate tensile stress (UTS) is reached, the composite shows a stress-strain behavior like the shape of plastic deformation exhibited by a metallic material due to the sequential pullout of the fibers until the final failure.…”

“…Figure 2 schematically shows the typical failure patterns found in ceramic composites [ 3 , 4 , 10 ]. As the load increases after the initial matrix cracking, phenomena such as interfacial debonding and sliding, crack deflection, and crack bridging between the fiber and the matrix material go through.…”