Machining of titanium alloy cutting processing big reveal

The cutting and machining performance of titanium alloy has been the key factor restricting its machining efficiency and quality.

Titanium alloys are characterised by high melting point (1668°C), high strength (σb≈450-1100MPa) and low density (ρ≈4.5g/cm³). In addition, titanium alloys have good corrosion resistance, fatigue strength and fracture toughness.

However, it is these properties that make titanium alloys have the following characteristics during cutting and machining:

1. large cutting force: due to the high strength and hardness of titanium alloy (HRB70-95), it makes the cutting force larger.

2. high cutting temperature: the thermal conductivity of titanium alloy is low (λ≈16.3W/(m-K)), and the heat generated in the cutting process is difficult to conduct quickly, resulting in a high temperature in the cutting zone.

3. Strong adhesion: the friction coefficient between titanium alloy and cutting tool is large (μ≈0.2-0.4), which is easy to produce adhesion phenomenon.

In view of the cutting characteristics of titanium alloy, it is necessary to choose cutting parameters reasonably in order to improve the machining efficiency and quality. The following are some suggestions:

1. cutting speed: due to the high cutting temperature of titanium alloy, the cutting speed should be reduced appropriately.

2. feed: titanium alloy cutting force is larger, the feed should be reduced appropriately.

3. depth of cut: the depth of cut has less effect on tool wear and machining quality, but too deep a depth of cut may lead to tool breakage.

4. cutting fluid: titanium alloy viscosity, the use of appropriate cutting fluid to help reduce friction, reduce cutting temperature, reduce tool wear. Commonly used cutting fluids are water-soluble cutting fluids, oil-soluble cutting fluids and so on.

In the cutting process of titanium alloy, the following problems may be encountered:

1. Tool wear: Due to the high cutting force, high temperature and high viscosity of titanium alloy, the tool is easy to wear. In order to improve tool life, high performance tools such as coated tools and carbide tools can be used.

2. Surface quality problems: Titanium alloy cutting process is easy to produce burrs, scratches and other surface quality problems. In order to improve the surface quality, you can appropriately reduce the cutting speed, feed, the use of appropriate cutting fluid, etc..

3. Dimensional accuracy problems: titanium alloy has a small modulus of elasticity and is prone to deformation. In order to improve the dimensional accuracy, you can use a rigid machine tool, a reasonable clamping method, etc.