Analysis Of Laser Cutting For Titanium Materials

Laser cutting is a commonly used high-precision process for processing titanium and titanium alloy materials. It is widely applied in aerospace, medical devices, chemical equipment, and other fields because of a small heat-affected zone, high-quality cutting edges, and strong flexibility,

 

 

The main technical principle of laser cutting is the thermal effect of high-energy-density laser beams and the vaporization cutting process:

 

1.A high-power laser is aimed to the surface of the titanium material. It can instantly raise the local temperature to titanium's boiling point and cause the material vapor rapidly and form holes.

 

2.Auxiliary gas is sprayed out through the cutting head nozzle. It blows away the vaporized titanium from the cutting zone and keeps air out. So it prevents titanium from reacting with oxygen at high temperatures and forms brittle titanium oxide.

 

3.When the laser beam and the workpiece move relative to one another, the holes will be stretched along the cutting path, and finally form a continuous cutting surface.

 

 

 

The physical properties affect their cutting difficulty and process particularities:

 

1.High reactivity: Titanium easily reacts with elements,like O, N, and H at high temperatures. The titanium oxide reduces the toughness of the cutting edge and may even cause cracks, so we need to use inert gas protection.

 

2.High thermal conductivity: Titanium has a lower thermal conductivity than steel, but it is higher than stainless steel. During cutting, heat is easily conducted to the surrounding area. It needs precise control of laser power and cutting speed to avoid an excessively large heat-affected zone .

 

3.High melting/boiling points: We need a laser beam with higher energy density. Usually, we should select a fiber laser and control the focused spot diameter between 0.1–0.3mm.

 

4.Cutting quality advantages: Unlike plasma cutting and waterjet cutting,Laser-cut titanium materials have smooth cross-sections and high perpendicularity, It can meet the requirements of high-precision components without following grinding.

 

 

1. Material Pretreatment and Clamping

Before cutting, remove oil stains and oxide scales from the titanium material surface to avoid impurities affecting cutting quality.

During cutting,use vacuum adsorption or special fixtures to hold the workpiece firmly in place,in order to stop thermal deformation from causing dimensional deviations.

 

2. Differences Between Thick Plate and Thin Plate Cutting

Thin plates (＜3mm): Increase the cutting speed , reduce laser power , and minimize the heat-affected zone. It can be suitable for precision part processing (medical implants).

Thick plates (＞10mm): Laser power needs to be increased, combined with pulse mode for segmental and multiple cutting. In the mean time, we need to increase the auxiliary gas pressure to ensure complete slag discharge.

 

 

Problems	Causes	Solutions
Oxidation and discoloration of cutting edges	Insufficient purity/low pressure of auxiliary gas	Use high-purity argon; increase gas pressure
Burrs on the cut	Focal position deviation/excessively fast speed	Calibrate the focal point; reduce cutting speed
Excessively large heat-affected zone	Excessively high laser power/excessively slow speed	Optimize power-speed matching; use pulsed laser
Plate deformation	Heat concentration/insufficient clamping	Add cooling measures; use multi-point fixtures for fixation