Double Disc Metallographic Pre-Grinding Machine with Speed 450rpm Water Cooling

Brief Introduction:

iqualitrol MP-2 is suitable for pre-grinding, grinding and polishing metallographic specimens. Since the machine is speed-adjusted by a transducer, it can run 450rpm and 600rpm , which favors the machine with wide applications.

The machine is equipped with cooling system which can cool down the specimen during rough grinding so as to prevent overheating and avoid damage the metallographic structure .

Featuring easy operation and reliable performance, it is an indispensable device for the factories, research institutions and college labs to prepare metallographic specimen.

Technical Specifications:

Surface layers damaged by cutting must be removed by grinding. Mounted specimens are ground with rotating discs of abrasive paper, for example wet silicon carbide paper.

The coarseness of the paper is indicated by a number: the number of grains of silicon carbide per square inch. So, for example, 180 grit paper is coarser than 1200 grit.

The grinding procedure involves several stages, using a finer paper (higher number) each time. Each grinding stage removes the scratches from the previous coarser paper.

This can be easily achieved by orienting the specimen perpendicular to the previous scratches. Between each grade the specimen is washed thoroughly with soapy water to prevent contamination from coarser grit present on the specimen surface. Typically, the finest grade of paper used is the 1200, and once the only scratches left on the specimen are from this grade.

The series of photos below shows the progression of the specimen when ground with progressively finer paper.

Polishing discs are covered with soft cloth impregnated with abrasive diamond particles and an oily lubricant or water lubricant.

Particles of two different grades are used: a coarser polish - typically with diamond particles 6 microns in diameter which should remove the scratches produced from the finest grinding stage,

and a finer polish – typically with diamond particles 1 micron in diameter, to produce a smooth surface.

Before using a finer polishing wheel the specimen should be washed thoroughly with warm soapy water followed by alcohol to prevent contamination of the disc. The drying can be made quicker using a hot air drier.

Mechanical polishing will always leave a layer of disturbed material on the surface of the specimen. Electropolishing or chemical polishing can be used to remove this, leaving an undisturbed surface.