Machining titanium rod hot extrusion is to extrude the powder under the condition of increasing the temperature, so that the product can achieve full densification. The hot extrusion method can accurately control the composition of the material and the internal structure of the alloy. The hot extrusion method can be divided into two forms: sheathed hot extrusion and non-sheathed hot extrusion.
For active metal titanium and titanium alloy powder, in order to prevent oxidation of the product, the sheathing hot extrusion method is often used. At this time, the sheath is prepared first, and the powder or compact is packed in the sheath. After pre-extracting and sealing, it is placed in an extruder for hot extrusion.
The covering material used at this time should have good thermoplasticity, not form full gold with the unwinding material, easy to peel off after hot extrusion, convenient source and low cost. Low-carbon steel or stainless steel sheets are more commonly used.
The first process of hot extrusion of titanium alloy rods is to combine forming, sintering and thermal processing to directly obtain drill products with better mechanical properties.
The second process is to shape titanium and titanium alloy powder. After sintering, the prepared sintered billet is hot extruded (for Ti-32Mo alloy, the temperature is 1000-1100°C) to obtain the properties of titanium alloy products. The influence of squeeze ratio on the properties of titanium materials. It can be seen from the table that a titanium material with a theoretical density of 98.6%-99.1% can be obtained.
The third process of titanium alloy rod is the process of filling the blank extrusion, which is an important method that can be used to produce products with complex cross-sections. The process includes: preparing a sheathing cavity, and determining the size of the cavity according to the required final product size plus the extrusion coefficient; Put the powder into the cavity and shake it firmly; evacuate, exhaust and seal the envelope; squeeze at a certain temperature and extrusion ratio; peel off the envelope.