The microstructure of materials mainly refers to

The microstructure of materials mainly refers to the composition forms of materials at the atomic, ionic and molecular levels.

Many properties of materials are closely related to the microstructure of materials. The microstructure of materials mainly includes the structures of crystals, organisms and cells under the microscope, as well as the structures of molecules, atoms and even subatomics.

microstructure analysis of building material

The microstructure, phase composition, phase transformation, micro-region, phase interface and surface chemical composition distribution of the materials were analyzed. Observe and analyze crystal segregation, crystal stillness, glass structure, molecular structure, chemical state (valence state, coordination number) electronic energy state of elements in materials, chemical environment around ions and bonding conditions. Various building materials have different microstructures, which determine their physical, chemical and mechanical properties.

Microscopic morphological observation method

Mainly observed by electron optical microscope.

Electron microscope, also known as electron microscope (hereinafter referred to as electron microscope analysis), is a technology that uses electron microscope to observe the microstructure of objects, mainly including the following:

1, electron microscope. An electro-optical instrument that uses high-speed electron beam as "light source" or excitation source to analyze and observe the microstructure of building materials. It can be divided into transmission electron microscope (TEM), scanning electron microscope (SEM), scanning transmission electron microscopy (STEM), reflection electron microscope (REM), point projection electron microscope (PEPM) and field emission electron (FEEM).

Among them, transmission electrons and scanning electrons are the most widely used. In recent ten years, analytical transmission electron microscope, analytical scanning electron microscope and surface microanalysis electron microscope with auger electron spectrometer (AES), scanning auger electron spectrometer (SAM), X-ray photoelectron spectrometer (XPS) and ultraviolet electron spectrometer (UPS) have been developed, which are widely used in the study of micro-area morphology, chemical composition, chemical valence state and electronic energy state of materials.

2. Transmission electron microscope. The high-speed electron beam emitted by the electron gun passes through the sample and is imaged and amplified by the electromagnetic lens, and the microscopic image of the sample is obtained on the terminal screen, TV screen or electrophotographic negative.

The electron magnification of transmission electron microscope can continuously change from several hundred times to more than 654.38+00000 times, and its point resolution is close to 654.38+0 angstrom, and its lattice resolution can reach within 654.38+0 angstrom, so that the arrangement images of single heavy atom and thin crystal in some special samples can be directly observed.

Generally, the accelerating voltage of electron gun for transmitting electricity is 50 ~ 150 kilogeneration. Ultra-high-speed electric sound can reach 500 kV to 3 kV, with strong electron beam penetration and small sample editing loss. An environmental sample room can be equipped to directly observe the chemical reaction and phase change process of materials in the natural environment.

The transmission electron microscope is developing to multi-function, which has the functions of transmission scanning, selected area electron diffraction, high-resolution electron diffraction, X-ray energy dispersion spectrometer, electron energy loss spectrometer and so on. The chemical composition, phase, crystal structure, chemical valence state and electronic energy state of elements can be analyzed comprehensively while observing the micro-morphology of the sample.

3. Scanning electron microscope. The electron beam scans the surface of the sample line by line, and interacts with the sample to generate information such as secondary electrons, backscattered electrons, X-rays, absorbed electrons and transmitted electrons, which are received and amplified by the detector, and the microstructure image of the sample surface is obtained on the TV screen. By receiving different excitation information, the secondary electron image, backscattered electron image and absorbed electron image of the sample can be obtained respectively.