Before titanium products are formed, they must be cut first. Titanium plate cutting also uses conventional punching, shearing, milling, and sawing methods. Due to the high strength of the titanium plate, it is different from aluminum alloy cutting.
1. Shearing
Raw materials or parts with straight shapes can be cut on a gantry shearing machine. If an ordinary shearing machine is used, carefully check whether the equipment can shear titanium plates. Titanium alloy plates with a thickness of less than 35 mm can be sheared to the required size under production conditions. If necessary measures are taken to avoid slipping during shearing, thicker plates can also be sheared. To prevent slipping, a larger clamping pressure is required. On the edge of the sheared titanium plate, especially for thicker titanium plates, the linear deviation is 0.25-0.50 mm, which is usually caused by the insufficient rigidity of the shear blade. Using a thicker shear blade can sometimes overcome this defect. If the material blocking device is modified and digital display, fine-tuning, and other technologies are used, the cutting accuracy can also be improved. The crack depth of the titanium plate edge does not exceed 0.4 mm, which can be removed by grinding and filing. If shearing will cause cracks in the key parts of parts, you should consider using a band saw or other titanium plate cutting method. When cutting with a gantry shearing machine, the minimum gap between the single sides of the scissors is 2-3% of the material thickness, the shearing angle is 75 degrees to 85 degrees, the back angle is 2 degrees to 3 degrees, and the blade inclination angle on the bevel shearing machine is 2 degrees to 5 degrees.
Titanium plates can also be cut with ordinary rolling shearing equipment. Circular shears can cut contours with large curvature radii (the minimum radius is about 250 mm). This method is used for titanium plates with a thickness of less than 2.5 mm. The current vibration shearing machine is only suitable for shearing titanium plates with a thickness of about 2 mm. The edges of the cut rough materials must be filed or ground, and a filing margin of more than 0.25 mm must be left. For thin materials (thickness <0.8 mm), when the quantity is small, lever-type manual shears or hand shears can also be used to cut materials.
2. Punching
Generally, the required shape of the rough material is punched out on the punching machine at one time. Usually, for rough materials with simple shapes, the maximum blanking thickness is about 3 mm. The titanium plate blanking die should have sufficient rigidity, and the guide column should be used to keep the upper and lower dies in an accurate relative position. When manufacturing various flat parts or rough materials of various shapes, the minimum size of the titanium plate blanking punching hole and the minimum radius of the edge of the punched parts should meet the requirements.
In addition, the punching and shearing machine can also be used for blanking. During processing, a crescent-shaped cut is punched out with a small punching die according to the template and connected to cut out the burr of the part, and then the key edge is trimmed. The edge quality and accuracy are not as good as the punching and shearing, and the efficiency is not high. The advantage of punching and shearing is that the production preparation cycle is short, and it is often used for small batch production.
3. Band saw
The band saw has high processing efficiency and convenient production preparation, but it is not suitable for processing too-thin materials. It is often used for titanium plate cutting with a thickness of more than 3 mm. This method does not produce edge cracks, but its disadvantage is that there are burrs, which must be polished after blanking. At present, most of them are used for edge trimming, trimming, and end cutting.
Band saw cutting can be divided into three categories: friction, semi-friction, and ordinary band saw. When the friction band saw is working, due to the high linear speed, there is intense friction between the saw blade and the workpiece, and the temperature in the cutting area is very high, which reduces the cutting resistance of the material, improves the processability, and is efficient.
The band saw used for titanium should be a rigid structure with sufficient power to maintain a constant speed during sawing; it should be able to automatically feed, tension the band, and provide sufficient coolant. The usual high-speed steel band saw can maintain a sharp edge and obtain stable results. The saw blade with a tungsten carbide blade is used to saw particularly thick materials, which can reduce the height of the burr and the depth affected by heat.
4. Milling
Use a milling cutter to cut a stack of titanium plates to the desired shape, titanium plate cutting and the milling head moves along the milling template, or a large CNC sheet metal milling machine is used for automatic milling. For stretched edges such as concave curves or flanging, the waist is polished before forming to prevent cracks.
