Titanium (especially Ti-6Al-4V) has low thermal conductivity, high strength, and a tendency to work-harden and react chemically with tools. Heat stays at the cutting edge instead of leaving with the chip, so the wrong numbers destroy tools fast.
Start with the right tools. Use fine-grain carbide with a sharp positive rake (8–15°) and AlTiN or TiAlN coatings. Avoid dull edges or heavy hone—they rub and harden the surface. For milling, 3–4 flute end mills work well; for turning, positive inserts with a small nose radius are preferred.
Cutting speed is the most critical lever. For Ti-6Al-4V with coated carbide, roughing typically runs 25–50 m/min (80–160 SFM). Finishing can stretch to 40–90 m/min (130–300 SFM) under light engagement. Commercially pure grades tolerate higher speeds. Going much faster spikes edge temperature and kills tool life; going too slow causes rubbing and work hardening. Always start conservative and increase only after verifying heat and chip color (silver/gold is good; blue/black means too hot).
Feed rates should stay high enough to form a real chip. Aim for 0.05–0.15 mm per tooth in milling roughing (higher with chip thinning in dynamic/HEM strategies) and 0.05–0.12 mm/rev in turning. Underfeeding is worse than overfeeding—rubbing generates heat without removing material. Depth of cut follows the same logic: axial depths of 0.5–2 mm for roughing are common, paired with low radial engagement (10–30% of tool diameter, or 5–15% in high-efficiency milling). This gives each flute time to cool.
Coolant is non-negotiable. High-pressure through-tool or flood coolant at 35–70+ bar directed at the chip root is ideal. It removes heat, breaks chips, and prevents re-cutting. Dry machining risks fire and rapid tool failure.
Toolpath strategy matters as much as the numbers. Prefer climb milling, constant engagement, and no dwells. Adaptive or trochoidal paths reduce peak loads and heat spikes. Rigid setups, proper fixturing, and sharp tools complete the system.
Test on a sample, watch tool wear and surface finish, then fine-tune. Optimal parameters balance speed, feed, and engagement so the chip carries heat away while the edge stays cool. Get these right and titanium becomes predictable instead of punishing.