MICRO EXAMINATION

 

Micro examination is performed on samples either cut to size or mounted in a resin mold. The samples are polished to a fine finish, normally one-micron diamond paste, and usually etched in an appropriate chemical solution prior to examination on a metallurgical microscope. Magnifications of x50 and above are used for micro examinations.

 

Most commonly it is carried out to assess the structure of material for following quality purposes:

• Examine for metallurgical anomalies such as third phase precipitates, excessive grain growth, etc.,
• Ensures correct heat treatment is employed,
• Detects unwanted phases and inclusions,
• Ensures castings are free from cracks or voids and segregations,
• Identifies where excessive grain growth has occurred,
• Determines fracture modes and corrosion damage in failure investigations.

 

 

 

APPLICATION STANDARD:

TS EN ISO 17639:                 Destructive tests on welds in metallic materials – Macroscopic and microscopic examination of welds.

Grain Size Analysis:              ASTM E112, DIN EN ISO 643, JIS G0551/0552

Nodular Cast Iron:                 ASTM 247, ISO 945-2, JIS G5502