Hydrostatic extrusion technology has a history of nearly one hundred years. However, in the process of large-scale and industrialization, the development speed is slowed down due to the limitation of higher strength structural materials. With the progress of material science, the practical application of this technology has been promoted. Using hydrostatic extrusion technology to extrude titanium screws has outstanding advantages. In recent years, superconducting materials are developing towards large cutting surface. Due to the higher and higher requirements for the continuity of conductor, the size and weight of ingot will inevitably be increased. In this way, it is difficult to use ordinary extrusion equipment, and hydrostatic extrusion technology has more advantages.
In metal processing, it is hoped that the machining parts can be in the state of three-dimensional compressive stress, because it is conducive to the plastic deformation of metal and the elimination of surface cracks and defects. In addition, it is also required to be in good lubrication state during processing to reduce the loss of function. If hydrostatic extrusion technology is used, the above two purposes can be satisfied.
1. Hydrostatic extrusion of titanium screw is in the process of non friction deformation. The friction between ingot and extrusion tool is the main obstacle of metal deformation. When hydrostatic extrusion is used, the high-pressure liquid separates the ingot from the wall of the extrusion cylinder. At the same time, some of the high-pressure liquid enters the mold hole, and the extruded products are also separated from the mold wall. Therefore, the friction coefficient can be as low as 0.01, which can greatly reduce the power loss and improve the surface accuracy of the products.
2. Increase the length of titanium screw ingot. Traditional extrusion method, 50% extrusion pressure is used to overcome the friction between ingot and extrusion tool. The friction force is proportional to the length of the ingot. Therefore, the length of ingot is limited. If hydrostatic extrusion is used, it is in the process of frictionless extrusion, so the ingot length can be increased. For example, for the same tonnage extruder, the output of hydrostatic extrusion can be increased more than three times than that of ordinary extrusion.