Sample Preparation Checklist

1. Pre-Preparation Planning

• Document as-received condition, orientation, and identifying marks before any cuts
• Identify material type and composition
• Determine analysis objectives (microstructure, hardness, etc.)
• Select appropriate sectioning method
• Plan mounting requirements (if needed)
• Review material safety data sheets (MSDS)
• Prepare work area and safety equipment

2. Sectioning

• Select appropriate cutting wheel/abrasive
• Set cutting parameters (speed, feed rate, coolant)
• Mark sample orientation (if important)
• Perform cut with proper technique
• Inspect cut surface for damage
• Clean sample to remove cutting debris
• Document section location and orientation

3. Mounting (if required)

• Select mounting material (compression, castable)
• Prepare sample surface for mounting
• Set mounting parameters (pressure, temperature, time)
• For compression mounts, cool under pressure to prevent shrinkage gaps
• Allow mount to cure completely
• Inspect mount for voids or defects
• Label mount with sample identification

4. Grinding

• Start with coarsest appropriate grit (typically 120-180)
• Rotate sample 90° between grits so new scratches run perpendicular to the previous set
• Apply consistent, moderate pressure
• Use adequate coolant/lubricant
• Grind until previous scratches are removed
• Rinse sample and platen thoroughly between grits
• Progress through grit sequence (240, 320, 400, 600; 800/1200 for fine work)
• Inspect surface after each grit
• Ensure all previous scratches are removed before proceeding
• Final grinding should produce uniform scratch pattern

5. Polishing

• Select appropriate polishing cloth
• Choose polishing compound (diamond, alumina, etc.)
• Set polishing parameters (speed, pressure, time)
• Apply polishing compound evenly
• Polish with consistent technique
• Rinse sample and platen between polishing steps
• Progress through polishing sequence (9um, 3um, 1um, 0.05um)
• If finishing with colloidal silica, flush with water for the last 30-60 seconds while polishing
• Inspect surface quality after each step
• Final polish should produce mirror-like surface
• Verify no scratches or contamination remain

6. Final Cleaning

• Rinse sample thoroughly with water
• Use ultrasonic cleaner if available
• Dry sample completely (compressed air, lint-free cloth)
• Inspect under microscope for cleanliness
• Ensure no polishing compound residue remains
• Handle sample carefully to avoid fingerprints

7. Etching (if required)

• Examine sample unetched first for graphite, inclusions, cracks, and porosity
• Select appropriate etchant for material
• Prepare etchant solution (always add acid to water, never water to acid)
• Test etchant on scrap sample first
• Apply etchant using proper technique (swab, immersion, electrolytic)
• Monitor etching time carefully
• Stop etching at appropriate time
• Rinse immediately; never let the etched surface dry before rinsing (critical with HF-bearing etchants)
• Dry sample completely
• Inspect etch quality under microscope

8. Quality Control

• Inspect sample under microscope at appropriate magnification
• Verify no scratches, relief, or contamination
• Check for proper microstructure revelation (if etched)
• Document any artifacts or issues
• Photograph sample if required
• Store sample properly to prevent damage

9. Documentation

• Record all preparation steps and parameters
• Note any deviations from standard procedure
• Document grit sizes and polishing compounds used
• Record etching details (if applicable)
• Save images/photographs
• Update procedure records

Notes