Tensile Fracture Behavior and Characterization of Ceramic Matrix Composites

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

Ceramic composite materials have been efficiently used for high-temperature structural applications with improved toughness by complementing the shortcomings of monolithic ceramics. In this study, the fracture characteristics and fracture mechanisms of ceramic composite materials were studied. The ceramic composite material used in this study is Nicalon ceramic fiber reinforced ceramic matrix composites. The tensile failure behavior of two types of ceramic composites with different microstructures, namely, plain-weave and cross-ply composites, was studied. Tensile tests were performed on two types of ceramic composite material specimens. Microstructure analysis using SEM was performed to find out the relationship between tensile fracture characteristics and microstructure. It was found that there was a difference in the fracture mechanism according to the characteristics of each microstructure. In this study, the results of tensile tests, failure modes, failure characteristics, and failure mechanisms were analyzed in detail for two fabric structures, namely, plain-weave and cross-ply structures, which are representative of ceramic matrix composites. In order to help understanding of the fracture process and mechanism, the fracture initiation, crack propagation, and fracture mechanism of each composite material are schematically expressed in a two-dimensional figure. Through these results, it is intended to provide useful information for the design of ceramic composite materials based on the mechanistic understanding of the fracture process of ceramic composite materials

Non-Destructive Characterization of Railway Materials and Components with Infrared Thermography Technique

Infrared (IR) thermography technology is one of the leading non-destructive evaluation (NDE) techniques based on infrared detection. Infrared thermography, in particular, has the advantage of not only being used in non-contact mode but also provides full images, real-time inspection, and relatively fast results. These advantages make it possible to perform thermal imaging analysis of railway materials and/or components, such as brake disc simulation, monitoring of abnormal heat generation, and monitoring of temperature changes, during mechanical tests. This study introduces the current state of research on railway materials and/or components using IR thermography technology. An attempt was made to characterize the deterioration of electrical equipment of diesel electric locomotives using infrared thermal imaging techniques. In addition, surface temperature monitoring was performed during tensile testing of railway steels using a high-speed infrared camera. Damage evolution due to the hot spot generation of railway brake discs was successfully monitored using high-speed IR cameras. In this paper, IR thermal imaging technology, used as a non-destructive evaluation analysis in the railway field, was introduced, and the results of recent research are presented

Underground Object Classification for Urban Roads Using Instantaneous Phase Analysis of Ground-Penetrating Radar (GPR) Data

Ground-penetrating radar (GPR) has been widely used to detect subsurface objects, such as hidden cavities, buried pipes, and manholes, owing to its noncontact sensing, rapid scanning, and deeply penetrating remote-sensing capabilities. Currently, GPR data interpretation depends heavily on the experience of well-trained experts because different types of underground objects often generate similar GPR reflection features. Moreover, reflection visualizations that were obtained from field GPR data for urban roads are often weak and noisy. This study proposes a novel instantaneous phase analysis technique to address these issues. The proposed technique aims to enhance the visibility of underground objects and provide objective criteria for GPR data interpretation so that the objects can be automatically classified without expert intervention. The feasibility of the proposed technique is validated both numerically and experimentally. The field test utilizes rarely available GPR data for urban roads in Seoul, South Korea and demonstrates that the technique allows for successful visualization and classification of three different types of underground objects

Mineral, metal ve malzemelerin Karakterizasyonu 2018

This collection gives broad and up-to-date results in the research and development of materials characterization and processing. Coverage is well-rounded from minerals, metals, and materials characterization and developments in extraction to the fabrication and performance of materials. In addition, topics as varied as structural steels to electronic materials to plant-based composites are explored. The latest research presented in this wide area make this book both timely and relevant to the materials science field as a whole. The book explores scientific processes to characterize materials using modern technologies, and focuses on the interrelationships and interdependence among processing, structure, properties, and performance of materials.Topics covered include ferrous materials, non-ferrous materials, minerals, ceramics, clays, soft materials, method development, processing, corrosion, welding, solidification, composites, extraction, powders, nanomaterials, advanced materials, and several others