Optical Microscopy

In metallography, optical microscopy is used to obtain the magnified images of polished or etched metal samples for macro or microstructure information.   The metallographic microscopes installed at EMSL’s materials science lab include various inverted or upright, stereoscopic and reflective light microscopes made by vendors such as Leica, Olympus, Nikon and Zeiss.  Our microscopes equipped with modules and PC-controlled digital camera to facilitate acquisition and analysis of images in various contrast modes such as brightfield, darkfield, differential interference and polarization. Optical microscopy analysis is often the first and important step we take before proceeding to scanning and/or transmission electron microscopy and other materials characterization analysis.  

SEM

Scanning electron microscopy (SEM) is a widely-used tool in the analysis of metals and alloys.  By combining with proper sample preparation and using appropriate imaging mode, SEM provides microstructural information such as surface morphology, grain structure and grain boundaries,  secondary phases and impurities, porosity and voids, chemical inhomogeneity, as well as micro- or nano-size structural or MEMS features.  SEM has been proven to be an essential and effective tool in the characterization of metallic materials, and in critical applications such as product quality control, identification, and failure analysis.  Typical imaging modes used in SEM analysis include secondary electron imaging, backscattered electron imaging, and elemental mapping when combined with an EDS detector.  The SEMs in service at EMSL include JSM-6510 and JSM-5610LV SEMs equipped with latest-technology EDS (EDX) detectors and analyzing software. 

EBSD

EBSD, or electron backscattering diffraction, is a technique that by combining with scanning electron microscopy, provides the information about crystal orientation and related microstructural information on the prepared sample surface.   By combining SEM, focused ion-beam (FIB) and EBSD, a volume of sample can be analyzed and 3-dimensional (3D EBSD) data can be presented.  EMSL provides EBSD and 3D-EBSD analysis at our NH Salem branch lab.  

TEM

Transmission electron microscopy (TEM) is widely used in the analysis of metals and alloys.  It provides variety of crucial information about grain and phase structure, crystalline defects and impurities, and local chemistry information when combined with EDS or other tools.  EMSL provide TEM analysis of steels and other types of alloys using JEOL-100CX, JEOL-2000FX, and JEOL-1200EX TEMs.