Search Results for microstructural analysis

Microstructural analysis reveals many important details about the qualities and capabilities of high-performance ceramics. This article explains how to prepare ceramic samples for imaging and the imaging technologies normally used. It describes sectioning, mounting, grinding, and polishing as well as ceramographic etching. It discusses common imaging approaches, including scanning electron microscopy and thin-section polarized light techniques, a type of optical microscopy. The article also addresses microstructural classification, examining detailed micrographs from samples of aluminum oxide, zirconium dioxide, aluminum nitride, silicon carbide, and piezoelectric ceramics.

Microstructural analysis is the combined characterization of the morphology, elemental composition, and crystallography of microstructural features through the use of a microscope. This article reviews three types of the most commonly used electron microscopies in metallurgical studies, namely scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy. It briefly describes the operating principles, instrumentation which includes energy dispersive X-ray detectors, spatial resolution, typical use of the techniques, elemental analysis detection threshold and precision, limitations, sample requirements, and the capabilities of related techniques.

Quantitative image analysis has expanded the capabilities of surface analysis significantly with the use of computer technology. This article provides an overview of the quantitative image analysis and optical microscopy. It describes the various steps involved in surface preparation of samples prone to abrasion damage and artifacts for quantitative image analysis.

Microstructural analysis of the composite matrix is necessary to understand the performance of the part and its long-term durability. This article focuses on the microstructural analysis of engineering thermoplastic-matrix composites and the influence of cooling rate and nucleation on the formation of spherulites in high-temperature thermoplastic-matrix carbon-fiber-reinforced composites. It also describes the microstructural analysis of a bio-based thermosetting-matrix natural fiber composite system.

This article describes testing and characterization methods of ceramics for chemical analysis, phase analysis, microstructural analysis, macroscopic property characterization, strength and proof testing, thermophysical property testing, and nondestructive evaluation techniques. Chemical analysis is carried out by X-ray fluorescence spectrometry, atomic absorption spectrophotometry, and plasma-emission spectrophotometry. Phase analysis is done by X-ray diffraction, spectroscopic methods, thermal analysis, and quantitative analysis. Techniques used for microstructural analysis include reflected light microscopy using polarized light, scanning electron microscopy, transmission electron microscopy, energy dispersive analysis of X-rays, and wavelength dispersive analysis of X-rays. Macroscopic property characterization involves measurement of porosity, density, and surface area. The article describes testing methods such as room and high-temperature strength test methods, proof testing, fracture toughness measurement, and hardness and wear testing. It also explains methods for determining thermal expansion, thermal conductivity, heat capacity, and emissivity of ceramics and glass and measurement of these properties as a function of temperature.

This article reviews how process variations influence the characteristics of thermal spray coatings. It describes various specimen preparation techniques, which allow accurate microstructural analysis. These techniques include sectioning, cleaning, mounting, planar grinding, fine grinding, rough polishing, and etching. The article provides information on the problems associated with specimen preparation. It concludes with a discussion on the various methods of analysis for thermal spray coatings.

The metallographic specimen preparation process for microstructural investigations of cast iron specimens usually consists of five stages: sampling, cold or hot mounting, grinding, polishing, and etching with a suitable etchant to reveal the microstructure. This article describes the general preparation of metallographic specimens and the methods of macroscopic and microscopic examination. Usually, gray-scale (black-and-white) metallography is sufficient for microstructural analysis of cast irons. The article discusses the use of color metallography of gray irons and ductile irons. It also presents application examples of color metallography.

Microstructural analysis of specialized types of magnetic materials is centered on the examination of optical, electron, and scanning probe metallographic techniques unique to magnetic materials. This article provides a comprehensive overview of magnetic materials, their characteristics and sample preparation procedures. It reviews the methods pertaining to the microstructural examination of bulk magnetic materials, including microscopy techniques specified to magnetic materials characterization, with specific examples. The techniques used in the study of magnetic domain structures (microstructure) include the magneto-optical Kerr method, the Faraday method, the Bitter technique, scanning electron microscopy (magnetic contrast Types I and II), scanning electron microscopy with polarization analysis, Lorentz transmission electron microscopy, and magnetic force microscopy. The article also illustrates the microstructure of different types of soft magnetic material and permanent magnets.

This article briefly discusses popular techniques for metals characterization. It begins with a description of the most common techniques for determining chemical composition of metals, namely X-ray fluorescence, optical emission spectroscopy, inductively coupled plasma optical emission spectroscopy, high-temperature combustion, and inert gas fusion. This is followed by a section on techniques for determining the atomic structure of crystals, namely X-ray diffraction, neutron diffraction, and electron diffraction. Types of electron microscopies most commonly used for microstructural analysis of metals, such as scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy, are then reviewed. The article contains tables listing analytical methods used for characterization of metals and alloys and surface analysis techniques. It ends by discussing the objective of metallography.

Proper sectioning of the surface to be examined is a very important step in preparing steel specimens. The first step in preventing damage to the metallurgical structure is to minimize the amount of sectioning that is done. This article discusses the various metallographic techniques, namely mounting, grinding, polishing, and etching involved in the microstructural analysis of carbon and alloy steels, case hardening steels, cast iron, ferrous powder metallurgy alloys, wrought and cast stainless steels, tool materials, steel castings, iron-chromium-nickel heat-resistant casting alloys and different product forms of steels.

This article reviews the properties of cast steels that are specified for liquid corrosion service at temperatures above and below 650 deg C. Stainless steel castings are usually classified based on their resistance to corrosion and heat and generally fall into one category or the other. The article describes alternate methods for classifying cast stainless steels, one is based on grade designations, the other on microstructural analysis. It also addresses heat treatment, pointing out its similarities with the thermal processing of wrought materials, and establishes the importance of mechanical properties in material selection. The article presents information on the selection process and provides a detailed list of heat-resistant cast steels and alloys. It also includes key manufacturing characteristics to aid in foundry and welding-related decisions.

Supercarburizing, also referred to as high-concentration carburizing, carbide-precipitation carburizing, and carbide dispersion, is a carburizing method that results in a large amount of dispersed particulate carbide, with carbon content as high as 2 to 3%, to obtain surfaces with high hardness and good wear resistance. This article briefly reviews the process of supercarburizing using conventional carburizing steel as well as steels developed for supercarburizing, including 20CrMnMo steel, 20Cr2Ni4 steel, 35Cr3SiMnMoV steel, and 20CrMnTi steel. In addition, it discusses supercarburized steel composition, carburizing characteristics, mechanical properties testing, and microstructure analysis of 35Cr3SiMnMoV steel.

The characterization, testing, and nondestructive evaluation of ceramics and glasses are vital to manufacturing control, property improvement, failure prevention, and quality assurance. This article provides a broad overview of characterization methods and their relationship to property control, both in the production and use of ceramics and glasses. Important aspects covered include the means for characterizing ceramics and glasses, the corresponding rationale behind them, and relationship of chemistry, phases, and microconstituents to engineering properties. The article also describes the effects that the structure of raw ceramic materials and green products and processing parameters have on the ultimate structure and properties of the processed piece. The effects that trace chemistry and processing parameters have on glass properties are discussed. The article describes mechanical tests and failure analysis techniques used for ceramics.

This article provides a general introduction of materials characterization and describes the principles and applications of a limited number of techniques that are most commonly used to characterize the composition and structure of metals used in engineering systems. It briefly describes the classification of materials characterization methods including, bulk elemental characterization, bulk structural characterization, microstructural characterization, and surface characterization. Further, the article reviews the selection of materials characterization methods most commonly used with metals.

Materials are selected and used as a result of a match between their properties and the needs dictated by the intended application. This article provides information on how the composition and structure determine the properties of materials. It describes common structural elements that are most important in materials. The article presents a historical perspective of the use of materials and illustrates the evolution of engineering materials.