Pure Silver
Purpose：Observe the microstructure of pure
silver. The electronics and electrical industries account for the largest
consumption of silver, primarily for electrical contacts, composites, and
soldering materials. Additionally, due to its lustrous white appearance, high
chemical stability, and collectible value, silver is widely used in jewelry,
decorations, silverware, cutlery, ceremonial gifts, medals, and commemorative
coins. Samples undergo cutting (TableCut200), mounting (TJ2228 cold-curing
resin), grinding/polishing (Alpha610), and etching with a 1:1 solution of 3%
hydrogen peroxide and ammonium hydroxide to observe the matrix microstructure.
Basic
Guide：
Cutting：1.Use
an S20 resin-bonded silicon carbide cutting wheel for pure silver. Refer to the
Trojan Cutting Guide for specific
models.
2.Use
a constant-speed cutting mode with a maximum cutting speed ≤0.25 mm/s.
Mounting：Silver
is soft and temperature-sensitive. Use cold-curing resin for mounting.
Grinding：1.Begin
with P400 silicon carbide sandpaper/lapping films until the sample surface is flat and cutting damage is
fully removed.
2.Continue
rough polishing with NL-CP hard-woven, durable synthetic polishing cloth and 9µm diamond polishing suspension.
3.Clean
the sample, sample holder, and hands after each grinding step.
Polishing：1.Clean
the polishing cloth, sample holder, and hands before polishing. Repeat cleaning
after each step.
2.Do
not mix polishing disks with different
abrasive particle sizes.
3.Rinse
the sample surface with alcohol and dry with a blower to remove water residue.
4.After
each polishing step, inspect under a metallographic microscope to ensure
scratch size matches the abrasive grit and direction is random.
5.Clean
polishing cloths with running water and a soft brush after use, then air-dry.
6.Dedicate
polishing cloths used for pure silver exclusively to silver samples.
