TiN, TiAIN

TiN and TiAlN are PVD hard coatings that add thin, wear-resistant, low-friction surfaces to tools and metal parts with minimal dimensional change.

Overview

TiN (titanium nitride) and TiAlN (titanium aluminum nitride) are PVD hard coatings applied as very thin ceramic-like films, typically a few microns thick. They increase surface hardness and reduce adhesive wear, galling, and built-up edge on cutting edges and sliding contact surfaces. TiN is a common general-purpose wear coating; TiAlN typically handles higher cutting temperatures and dry/high-speed machining better due to improved hot hardness and oxidation resistance.

Choose TiN/TiAlN when the base material has adequate core strength but the surface needs longer life under abrasion or sliding contact. Typical tradeoffs: line-of-sight deposition can leave deep recesses with less coverage; sharp edges can thin out or chip; coating adds little corrosion protection on its own. Masking and fixturing drive cost, and the coating can slightly change surface finish and critical fits.

Common Materials

  • Tool steel
  • H13 steel
  • D2 steel
  • Carbide
  • Stainless steel
  • Titanium Grade 5

Tolerances

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Applications

  • End mills and drills
  • Taps and thread mills
  • Punches and dies
  • Injection mold cores and inserts
  • Wear pads and sliding components
  • Gauges and fixtures exposed to abrasion

When to Choose TiN, TiAIN

Pick TiN or TiAlN when you need a thin, hard, wear-resistant surface without changing the part geometry or heat-treat condition. It fits best for tools and wear parts with accessible surfaces and defined contact zones, from prototype through production. Expect the biggest ROI when wear, galling, or built-up edge is limiting tool life or causing inconsistent performance.

vs Diamond-like Carbon (DLC)

Choose TiN/TiAlN when you need higher temperature capability on cutting edges and strong performance in abrasive metal cutting. TiAlN in particular holds hardness better at elevated cutting temperatures where many DLC coatings lose performance. For low-temperature sliding and very low friction requirements, DLC is often the better fit.

vs Electroless nickel plating (EN)

Choose TiN/TiAlN when wear resistance and edge retention are the priority and you can accept line-of-sight PVD coverage. EN is better for uniform coverage in recesses and for corrosion protection, but it won’t match TiN/TiAlN hardness and tool-life gains in cutting applications. Use TiN/TiAlN when you’re protecting a working surface, not trying to build thickness.

vs Hard chrome plating

Choose TiN/TiAlN when you want a very thin coating with minimal dimensional impact and high hardness without hydrogen embrittlement concerns. Hard chrome is a thicker build and can be useful for size restoration, but it can introduce fit changes and has process/environment constraints. TiN/TiAlN is a better match for sharp edges and precision tools where thickness control matters.

vs Nitriding (gas or plasma)

Choose TiN/TiAlN when you need a hard surface on materials that don’t nitride well or when you need a defined coating with low process temperature and little distortion. Nitriding creates a diffusion case that follows all surfaces (including recesses) and can support heavy contact loads, but it depends strongly on alloy chemistry and heat treat. TiN/TiAlN is a straightforward add-on for tool steels and carbide tools when you mainly need wear resistance at the surface.

Design Considerations

  • Specify which surfaces are critical to coat and which must be masked, and include a coating map if fits or threads are involved
  • Call out coating type (TiN vs TiAlN), target thickness range, and any max thickness allowed on tight fits
  • Avoid extremely sharp edges; add small edge breaks or radii to reduce thinning and chipping at edges
  • Design to line-of-sight deposition: deep, narrow slots/holes may coat unevenly unless fixturing and rotation are planned
  • Define pre-coat surface finish and post-coat requirements (e.g., no polishing, or Ra target) to control friction and fit
  • Note the base material, heat treat condition, and any temperature limits so the coater can select the right PVD cycle