eTraining Introduction

Specimen Preparation

Leica Ultracut UCT

Histology

JEOL JSM-6400 SEM

Hitachi S-4700 FE-SEM

Hitachi FB-2000A FIB

Microanalysis

Veeco Dim 3000 AFM

Fluorescence Microscopes

Support

Metallurgical

Steel Polishing Procedure

Procedure by Ruth Kramer.

NOTE: If the ultrasonic cleaner is left on overnight, the water will evaporate and the unit will be destroyed. There is a new one in the lab which has a timer which should help avoid this possibility. However, there is a "hold" setting on the timer that will leave the unit on indefinitely. Please do not use the "hold" feature.

General Precautions

Polishing Procedure

1. Turn on the water lines to the grinder/Handimet if needed.    
2. Start with the 120 grit polishing wheel for coarse grinding. The purpose of this step is to remove the deformation produced during sectioning, and to produce an initially flat surface. First, turn on the wheel by pulling out the knob on the front of the machine, and turn on the "wheel wash" knob. Then, bevel the edges of the mount (you can bevel the back if they are sharp). Next, holding the mount flat against the grinding surface, grind without turning the specimen until the specimen surface is flat and streaked from the polishing abrasive. Try to avoid lifting the specimen from the wheel as much as possible—repositioning will frequently lead to a faceted surface rather than a flat one! WATCH TO MAKE SURE THE DRAIN IS NOT PLUGGED. If you hear a sound like fabric tearing, or water backs up in the sink or starts to overflow onto your feet, TURN OFF THE WATER TO BOTH WHEELS and get Ruth IMMEDIATELY.

Put a note on the wheels "NOT TO USE" if you cannot find Ruth right away AND email her at ruthie@mtu.edu.
VIEW
3. Fine Grinding: Turn on the water at the Handimet, and hold the specimen so that the direction of abrasive motion along the strip will be different than the direction of the scratches from coarse grinding. VIEW
4. Moving the specimen away from you along the 240 grit strip, count the number of strokes it takes to remove the scratches from the previous step, then repeat that number. Repeat this step for each successively finer grit abrasive paper on the Handimet (normally 240 - 320 - 400 - 600). VIEW
5. Rough Polish: Wash the sample with soap and cotton ball. Place the specimen on edge (preferably in a beaker of alcohol for steels) in the ultrasonic bath for a minute or so, and rewash with cotton (except for SEM samples—DO NOT use cotton after cleaning) and running water. THIS STEP IS NECESSARY FOR ALL FOLLOWING STEPS!!! VIEW
6. Use 6 µ diamond in the polishing room. Activate the wheel by pulling out the knob. Do not exceed 200 rpm and DO NOT USE RUNNING WATER. Hold the specimen in contact with the wheel surface, moving it counter to the direction of wheel spin, gradually moving towards the outer edge of the wheel. Use the bottles of diamond lubricant if needed. The amount of lubricant should be sufficient only to feel slight resistance against the wheel. Too much oil prevents a good contact between abrasive and specimen. Polish until the previous parallel scratches are gone. Look at the sample in the microscope to make sure—compare to the photos in the wall. VIEW
7. Wash as before, with cotton (except for SEM samples—DO NOT use cotton after cleaning) and soap and water, then ultrasonic bath, soap and water, and methanol. Be sure to wash your hands WELL after this step because abrasive on your fingers will contaminate the next polish! VIEW
8. Fine Polish: .05 µ alumina slurry in water, using the same technique as for 6 µ diamond, except water is the lubricant if needed. VIEW
9. Wash with soap and cotton (except for SEM samples—DO NOT use cotton after cleaning), ultrasonically clean, rewash, and rinse and dry with methanol. VIEW
10. If the sample is porous, drying the sample with the blow-dryer helps prevent bleed out of water in the pores. VIEW

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