Metallographic preparation of e-glass-epoxy composite material

Abstract

A method of preparing samples of a E-glass-epoxy composite material for moscopic examination thereof comprising the steps of first rough grinding the sample to produce a flat surface, fine grinding the sample in a series of grinding steps, each step accomplished with a finer grit of fine grinding material to obtain a relatively flat, scratch-free surface and then polishing the sample in a single polishing step to produce a sample with a scratch-free polished surface.

I claim: 
     
       1. A method of preparing samples of E-Glass-Epoxy composite material for microscopic examination thereof comprising the steps of: a. selecting a sample from the parent material;   b. encapsulating said sample;   c. rough grinding said sample for removing rough edges resulting from the cutting operation, said rough grinding being accomplished on a belt surfacer using a 180 grit silicon carbide belt with water soluble oil as a lubricant;   d. cleaning said sample in running water;   e. fine grinding said sample on a pregrinder in a series of grinding steps with water soluble oil as a lubricant, each step accomplished with a finer grit of grinding material to obtain a relatively flat, scratch-free surface;   f. cleaning said sample in running water;   g. polishing said material on a flat bronze wheel covered with a microcloth impregnated with a water slurry of 0.3 micron alumina powder and a liquid detergent by applying varying pressures for a predetermined length of time; and,   h. cleaning and drying said sample.   
     
     
       2. A method of preparing samples of E-Glass-Epoxy composite material as set forth in claim 1 wherein said series of fine grinding steps is four grinding steps; said first grinding step being accomplished using a 240 grit silicon carbide grinding material; said second grinding step being accomplished using a 320 silicon carbide grinding material; said third grinding step being accomplished using a 400 grit silicon carbide grinding material and said fourth grinding step being accomplished using a 600 grit silicon carbide grinding material to obtain said relatively flat, scratch-free surface. 
     
     
       3. A method of preparing samples of E-Glass-Epoxy composite material as set forth in claim 2 wherein said step of polishing said material by applying varying pressures for a predetermined length of time consists of applying heavy pressure for 10-15 seconds and subsequently applying light pressure for 10-15 seconds, said pressures being applied for said predetermined time at a grinding wheel speed of 1,000 RPM.