Grain Size

Grain size analysis measures the grain size of a metallic specimen. An accurate assessment of grain size in the specimen is used to verify the effectiveness of a particular manufacturing process, such as heat treating or tempering.

 

To prepare the specimen a technician mounts a cross section, polishes it and etches it. The grain is revealed by the etching. Next they create a photomicrograph and perform one of the following procedures:

 

  • Comparison ProcedureThe photomicrograph is scaled to 100x and compared to a reference chart.
  • Intercept ProcedureA concentric circle graph is superimposed on the image and the technician counts the number of interceptions on the circles with grain boundaries. 
  • Planimetric ProcedureA circle is superimposed on the image. The technician counts the number of grains found within the circle, and divides the area of the circle by the number of grains to find the average grain size.

 


Get started today. Contact us for a quote, more information, or answers to your questions. Click here.

 


Grain size analysis is performed according to ASTM E112 Determining Average Grain Size.

Applicable Specifications
ASTM E112
 

Metaltest Accreditations

NADCAP
Materials Testing

prilogo
AC7006
Scope of Approvals

Aerospace Approvals

Metaltest is OEM approved to perform military and commercial aerospace testing for a wide range of prime contractors including:

  • Boeing
  • Bombardier
  • Cessna
  • Goodrich
  • Gulfstream
  • Hawker Beechcraft
  • Sikorsky

Nuclear Approvals

Metaltest is NQA-1 Compliant for nuclear power testing. Our clients include:

  • ABW Technologies 
  • Alaskan Copper

Industry Associations

Metaltest holds memberships in the following industry associations:

Site Login

Get started today. Contact us for a quote, more information, or answers to your questions. Click here.