Under the optical microscope, the science of studying the rules of the structure and morphology of metal materials is called metallography. Metallographic analysis is an indispensable and important means for testing material structure and ensuring product quality. With the development of science and technology, especially optical technology, the performance of optical microscopy is expanding gradually, such as dark field, polarization, phase contrast, differential interference, infrared and ultraviolet light applications, etc. to improve the clarity and resolution of metallographic structure.
Analysis of projects and standards
Test material | Test project | Test standard |
Ferrous material | Conventional analysis, decarbonization layer, inclusions, grain size (including general steel and stainless steel), hardness gradient, macro specimen, welding structure (including heat affected zone, weld, base metal) | GB/T 6462-2005,GB/T 13299-1991,JB/T 7710-2007,JB/T 7713-2007,GB/T 13320-2007,GB/T 11354-2005,JB/T 9211-1999,JB/T 6141.2-1992,JB/T 6141.3-1992,QC/T 29018-2005 QC/T 262-2005,GB/T 1299-2000,JB/T 1255-2001,GB/T 7216-1987,GB/T 9441-1988,JB/T 9204-1999,GB/T 14979-1994,GB/T 9450-2005,ISO 2639:2002(E),GB/T 9451-2005,ISO 4970:1979(E),GB/T 224-1987,ISO 3887:2003(E),GB/T 5617-2005,ISO 3754:1976(E),GB/T 10561-2005,GB/T 4335-1984, ASTM E45-2005e2,DIN 50602-1985,YS/T 347-2004, GB/T 3246.1-2000,GB/T 9441-1988,GB/T 7216-87 GB/T 6394-2002,ASTM E112-1996(2004)e2 |
Copper and copper alloys | Microstructure and grain size | QJ 2337-1992,YS/T 347-2004 |
Aluminum and aluminum alloys | Examination methods for grain size, deformed aluminium and aluminium alloy products of cast aluminium alloy metallographic casting Al-Si alloy modification, cast aluminium alloy metallographic casting Al-Si alloy overburning, cast aluminium alloy metallographic casting Al-Si alloy pinhole, cast aluminium alloy metallographic casting Al-Cu alloy grain size, deformed aluminium and alumini | JB/T 7946.1-1999、JB/T 7946.2-1999、JB/T 7946.3-1999、JB/T 7946.4-1999、GB/T 3246.1-2000 |
Test process
In metallographic analysis, samples should be prepared according to various inspection standards and regulations. If improperly prepared, false phenomena may occur, thus drawing wrong conclusions. Therefore, the preparation of metallographic samples is very important. Usually, the preparation steps of metallographic samples are sampling, mosaic, labeling, grinding, polishing and etching. But not every metallographic specimen must go through the above steps. If the selected sample is suitable in shape and size for grinding, no mosaic is necessary. If non-metallic inclusions in metal materials or graphite in cast iron are examined, no etching is necessary. In a word, the procedure of sample preparation should be determined according to the purpose of inspection.
Test equipment
The Metal Laboratory is equipped with a complete set of Buehler's metallographic sample preparation equipment and Zeiss's positive metallographic microscope in Germany, which can realize professional metallographic analysis from ferrous to non-ferrous metals.