Titanium is a very active metal element that interacts with all elements. When heated, titanium interacts with oxygen to form an oxide film on its surface. The structure and properties of oxide films are different at different heating temperatures. The hot forming of
titanium plate is more complex, and the mechanical properties of each batch are not the same. In order to ensure the quality of the material, the manufacturers have certificates and test reports.
1. Requirements on the supply status of raw materials for titanium plate preparation
The primary deformation of
titanium sheet, rolled into sheet in a metallurgical plant, has poor repeatability. Domestic and foreign production of the same composition of titanium plate, mechanical properties are not small difference; The plate produced by different domestic factories, the performance will not be the same, even if the product of a factory, its mechanical properties of different furnace numbers are not the same. So in order to ensure the quality of parts, we should first ensure the quality of raw materials. The titanium and titanium alloy sheet material obtained from the warehouse shall be provided with the factory factory delivery certificate and the factory reinspection certificate. The certificate of conformity should be kept for future verification. If necessary, the workshop may keep a record of the basic information of each sheet fabricated part for reference.
All plates are required to be supplied in annealed state. In order to ensure the quality of the parts, the oxide layer and other pollution on the plate surface should be removed. The surface of the titanium plate shall not have cracks, peeling, folding, inclusions and other defects, as well as traces of pickling. Sheet material should be flat and paper-wrapped out of the warehouse. Care should be taken to prevent surface scratches during subsequent blanking, forming, assembly, transportation and storage.
2. Titanium plate blank blanking
There are many similarities in the wool preparation methods used in various sheet metal parts. Because the thickness of the titanium plate used is generally below 2 mm, and the thickness of 1.5 mm or more parts are few, so the titanium plate can be used to the existing equipment at room temperature.
When cutting, attention should be paid to make the wool edge smooth as far as possible, especially to prevent edge cracks, gnawing and shear marks and other defects, in the shear of thick plate should be paid more attention to.
The wool should be deburred and sharp edges removed before forming. Since the titanium plate is very sensitive to crack growth, this work is extremely important to eliminate stress concentration and prevent the wool from cracking and scratching the mold during forming. It can be deburred or polished by filing, sanding or sandpaper.
It should be noted that no matter which method is used to cut the material, only non-polluting ink and pen can be used when drawing the line. Steel printing is not allowed on the wool, only offset printing or special label can be used.
3. Oil removal and cleaning before forming
Before any thermoforming, grease or other dirt should be removed from the surface to avoid contamination of the titanium during heating. In addition, oxides on the wool surface reduce the plasticity of the material and should be removed before forming. Therefore, in order to reduce all kinds of influences in the atmosphere environment, vacuum quenching furnace and vacuum annealing furnace are generally used to heat, and the inert gas in the vacuum furnace can protect titanium and titanium alloy materials from pollution in the heating process.
