Coating Selection for Stainless & Titanium
Introduction
Choosing the right coating is one of the most important factors in achieving consistent machining results for stainless steel and titanium alloys.
These materials generate high cutting temperatures and cause rapid tool wear if the surface treatment is not optimized.
At HANYANG Tools, we carefully match PVD coatings to each application to ensure durability, heat resistance, and smooth chip evacuation.
1️⃣ Why Coating Matters
Both stainless steel and titanium have low thermal conductivity — meaning heat stays near the cutting edge.
An effective coating helps by:
💠 Reducing friction
💠 Improving heat resistance
💠 Preventing built-up edge (BUE)
💠 Extending tool life
Without the right coating, even a high-quality carbide tool can lose its edge after a few passes.
2️⃣ For Stainless Steel: TiAlN and AlTiN
Stainless steel is tough and work-hardens easily, demanding coatings that can handle high heat.
💠 TiAlN (Titanium Aluminum Nitride):
- Excellent heat resistance up to ~800°C
- Strong oxidation protection
- Ideal for dry or semi-dry cutting
- Performs well in austenitic and martensitic stainless grades
💠 AlTiN (Aluminum Titanium Nitride):
- Higher aluminum ratio improves surface hardness
- Forms a protective Al₂O₃ layer during cutting
- Suitable for harder stainless steels and higher-speed operations
Engineer’s Note:
HANYANG’s TiAlN/AlTiN-coated end mills undergo micro-edge polishing before coating to prevent micro-cracks and ensure coating adhesion.
3️⃣ For Titanium Alloys: TiSiN and DLC
Titanium has high strength and low conductivity, which easily leads to built-up edge and adhesive wear.
To combat these issues, coatings must reduce friction and withstand extreme heat.
💠 TiSiN (Titanium Silicon Nitride):
- Extremely hard (~4000 HV)
- High oxidation resistance (~1000°C)
- Perfect for high-speed dry machining of titanium and nickel alloys
💠 DLC (Diamond-Like Carbon):
- Ultra-smooth surface lowers friction
- Reduces built-up edge and material adhesion
- Excellent for titanium, aluminum, and composite materials
DLC-coated tools often achieve 30–50% longer tool life in aerospace titanium machining.
4️⃣ Coating Process and Quality Control
All coatings at HANYANG Tools are applied through advanced PVD (Physical Vapor Deposition) systems.
Each batch undergoes:
💠 Pre-cleaning and ultrasonic degreasing
💠 Temperature-controlled deposition
💠 Adhesion and thickness inspection
💠 Optical surface measurement
Result: consistent coating quality, reliable cutting edges, and improved heat dissipation.
5️⃣ Matching Coating to Application
When selecting coatings, consider:
| Material | Recommended Coating | Cutting Condition |
|---|---|---|
| Stainless Steel (304 / 316) | TiAlN / AlTiN | Dry or semi-dry, moderate speed |
| Hardened Stainless (420 / 440C) | AlTiN | High speed, finishing |
| Titanium Alloy (Ti-6Al-4V) | TiSiN | High temperature, dry cutting |
| Aerospace Titanium | DLC | Semi-dry, high precision |
💡 Tip: Always match coating hardness and temperature range with your cutting environment.
Conclusion
Coating is not just a surface finish — it’s a key factor in cutting tool performance.
By choosing the right coating, machinists can minimize wear, maintain dimensional accuracy, and extend tool life dramatically.
At HANYANG Tools, we combine precision geometry, PVD coating technology, and strict inspection to deliver carbide tools optimized for every material.