What is the best tool for cutting titanium?

The selection of tools for cutting titanium and titanium alloys depends on the specific processing method (such as milling, turning, drilling, etc.), and takes into account the characteristics of titanium: high chemical activity, low thermal conductivity, and easy work hardening. The focus is on reducing tool wear and controlling cutting temperatures. The following are the best tools for different processing scenarios:

Milling is the primary method for machining complex contours on titanium alloys. Ultrafine-grain carbide tools are the preferred choice, offering an optimal balance of hardness, wear resistance, and impact resistance.

Base material: Choose a WC-Co alloy with an 8%-12% cobalt content. (Too high a cobalt content can easily cause adhesive wear due to titanium's chemical affinity, while too low a cobalt content can result in insufficient impact resistance.)

Coating Optimization: AlCrN (aluminum chromium nitride) coating is preferred, as it has an oxidation resistance temperature of over 1100°C and reduces chemical reactions at high temperatures. TiAlN (titanium aluminum nitride) coating is an option for medium cutting speeds, offering superior wear resistance in the 600-800°C range.

Cutting Edge Design: A sharp, positive rake angle (5°-10°) and a small cutting edge radius (≤0.02mm) are recommended to minimize compression on the titanium material and reduce work hardening. For rough milling, a corrugated edge or chip splitter can be used to improve chip evacuation efficiency. Special scenarios: Metal ceramic tools (such as TiC-Ni-Mo series) can be used for high-precision finishing (such as medical implants), but they have poor impact resistance and are only suitable for small cutting volume processing.

Turning requires a balance between continuous cutting stability and anti-sticking properties:

Conventional turning: TiAlN or AlCrN-coated carbide inserts (such as ISO P or M types) are preferred. At cutting speeds of 50-100 m/min, their wear resistance and tool life are far superior to uncoated tools.

High-precision/high-surface-quality machining: Cubic boron nitride (CBN) tools are suitable for fine turning with small stock additions. They have a hardness exceeding HV3000 and are highly resistant to high temperatures (1400°C), preventing sticking wear on titanium. However, they are brittle and require low feed rates (0.05-0.1 mm/min).

The key to drilling is to address the issues of difficult chip removal and drill bit burnout:

General drilling (diameter <10mm): Cobalt-containing high-speed steel drills (HSS-Co, with a cobalt content of 5%-8%) offer better value for money, possess higher red hardness than ordinary HSS, and feature internal coolant holes (high-pressure cutting fluid delivered through the center hole) for effective heat dissipation and chip removal.

For deep holes or large-diameter drilling (diameter >10mm): Solid carbide drills (such as WC-Co alloy with a TiAlN coating) offer superior rigidity and wear resistance, suitable for high feed rates of 0.1-0.2 mm/min.

Band Saw Blades: Choose high-speed steel band saw blades (HSS-M42). These blades have a high cobalt content, excellent red hardness, and can withstand high cutting temperatures. Fine-tooth design reduces impact on the material and facilitates chip removal.

Circular Saw Blades: Carbide circular saw blades (such as WC-Co alloy with a TiN coating) are suitable for sawing larger titanium materials. The coating improves wear resistance and adhesion resistance, ensuring stable cutting.

When high-precision surface machining is required, CBN grinding wheels are the best choice: they offer high hardness, excellent wear resistance, and the ability to maintain cutting performance even at high temperatures. They also have a low chemical affinity with titanium, preventing adhesion and ensuring high-quality ground surfaces. For rough grinding, a coarser grit size improves efficiency, while for fine grinding, a finer grit size ensures precision.

In summary, titanium cutting tools must be selected specifically for the machining method, while cutting parameters (such as low cutting speeds and adequate cooling) must be coordinated to achieve efficient, high-quality machining.