Material-Specific Preparation Guide

Grinding: Start with 120 grit SiC, progress through 240, 400, 600 (800 and 1200 optional for high-quality work or high-magnification analysis)

Polishing: 9μm → 3μm → 1μm diamond, final with 0.05μm colloidal silica

Etching: 2-5% Nital or Picral, depending on structure to reveal

Notes: Standard preparation sequence, adjust grits based on hardness. Use 800/1200 grit for very fine finishes or when preparing for high-magnification analysis.

Grinding: Start with 120 grit, progress through 240, 400, 600 (800 and 1200 optional for high-quality work or high-magnification analysis)

Polishing: 9μm → 3μm → 1μm diamond, final with 0.05μm colloidal silica

Etching by class:

• Austenitic (304, 316): 10% oxalic acid electrolytic at 6 V, or Glyceregia by swab.
• Martensitic / PH (410, 420, 431, 17-4): Vilella's Reagent (1 g picric + 5 mL HCl + 95 mL ethanol).
• Ferritic (430, 446): Vilella's or Marble's.
• Duplex (2205, 2507): Beraha's I or Klemm's I — color contrast distinguishes ferrite from austenite.

Notes: Work-hardening material — use consistent moderate pressure. Use 800/1200 grit for very fine finishes. Vilella's does not etch 304/316 austenitic effectively, despite the popular shorthand of "Vilella's for stainless."

Grinding: Start with 120 grit, progress through 240, 400, 600

Polishing: 9μm → 3μm → 1μm diamond, final with 0.05μm colloidal silica

Etching: Keller's Reagent or Al-NaOH etchant

Notes: Soft material, use shorter times and lighter pressure to avoid smearing