7050 Aluminum Alloy
Purpose：Observe
the microstructure of aluminum alloy. Aluminum alloys are widely used in
aerospace, automotive, construction, and household industries due to their
lightweight properties, high specific
strength, corrosion resistance, and aesthetic appeal. As aluminum purity
increases, its hardness decreases, making it more prone to mechanical
deformation and scratches. In high-purity aluminum, grinding may cause severe
deformation or abrasive embedding, posing significant challenges during sample
preparation. Samples undergo cutting (TableCUT-200), cold mounting (TJ-2568),
grinding/polishing (Alpha-610), and etching with Keller’s reagent to observe
the microstructure (MN80).
Basic
Guide：
Cutting：1.Use
a resin-bonded silicon carbide cutting wheel for aluminum alloys. Refer to the
Trojan Cutting Guide for specific
models.
2.Select
pulse mode for cutting, with a recommended maximum cutting speed ≤0.25 mm/s.
Mounting：Use
cold-curing resin with high edge retention.
Grinding：1.Begin
with P400 silicon carbide sandpaper/lapping films until the sample surface is flat and cutting damage is
fully removed.
2.Continue
grinding with P800, P1200, P2000 and P4000 sandpaper.
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 cloths 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 aluminum alloys exclusively to such samples.
