Titanium alloy forging trimming must meet the following requirements:
- The cut is smooth, and the metal on the blank must not fall.
- The part adjacent to the cut surface of the blank must not be cracked, nor should there be uneven grain size caused by uneven deformation of the cut edge.
- No punch impression should be left on the trimmed blank, and the punch and parts should be completely consistent in shape.
When the batch size is small, you can use the milling machine to cut the edge or use the band saw and the specially designed friction plate to remove the burr. Regardless of the size or batch size of the large forgings and thick burrs, it is inconvenient to thermally trim the edges, and flame cutting is an effective method. Oxygen-gas, plasma, and other technologies can be used to successfully and economically cut burrs of 50 mm or more. After flame cutting, heat treatment should be performed to make the heat affected zone mechanically machined.
For larger batches of small and medium-sized titanium alloy forgings, the die is usually trimmed with a die on a crank press, and the trimming is performed at 600 to 800°C. If trimming must be performed immediately after trimming, the trimming temperature should be close to the upper limit. Titanium alloys are rarely trimmed with a mold in the cold state. Because the flash is very hard and brittle, it is easy to cause uneven cuts and even cause the risk of metal cracking and rapid chipping. For some alloys with a high degree of alloying, cold trimming It will cause cracks in the shear plane, and the cracks will spread into the metal from time to time.