Smelting and casting process of titanium and titanium alloys
The smelting and casting process of titanium and titanium alloys is a very important part of modern industry. Titanium has excellent properties such as low density, high strength, good corrosion resistance and biocompatibility, so it is widely used in aerospace, shipbuilding, chemical industry, medical equipment and other fields.
The titanium smelting and casting process mainly includes raw material preparation, smelting, pouring and post-processing steps. First, the raw material preparation stage requires refining titanium ore to obtain pure titanium metal. Then, the titanium metal is put into a furnace for smelting, usually an electric arc furnace or an electroslag furnace. After smelting is completed, the molten titanium metal is poured into a casting mold to form the desired product. Finally, through post-processing processes such as heat treatment and mechanical processing, the titanium products meet the required performance requirements.
Titanium is a very active metal. In the liquid state, it reacts very quickly with oxygen, nitrogen, hydrogen and carbon. Therefore, titanium alloy smelting must be carried out under the protection of a high vacuum or inert gas (ar or ne). The crucibles used for smelting all use water-cooled copper crucibles. There are three main methods of specific smelting processes: (1) Non-consumable electrode electric arc furnace smelting. Alloy smelting is performed under vacuum or inert gas protection. This process mainly prepares electrodes by smelting consumable electrodes. (2) Vacuum consumable electrode arc furnace smelting uses a consumable electrode made of titanium or titanium alloy as the cathode, and a water-cooled copper crucible as the anode. The molten electrode enters the crucible in the form of droplets, forming a molten pool. The surface of the molten pool is heated by the arc and is always in a liquid state. The surrounding areas where the bottom and the crucible are in contact are forced to cool, resulting in bottom-up crystallization. The molten metal in the molten pool solidifies into titanium ingots. (3) Schematic of the vacuum consumable electrode shell-protected smelting device. This kind of furnace is developed on the basis of vacuum consumable electrode electric arc furnace. It is a furnace type for casting special-shaped parts that combines smelting and centrifugal pouring. Its biggest feature is that there is a thin solid shell of titanium alloy between the water-cooled copper crucible and the metal melt, which is the so-called condensation shell. This layer of condensation shell of the same material serves as the lining of the crucible to form a molten pool to store the titanium liquid. , to avoid contamination of the titanium alloy liquid by the crucible. After pouring, a layer of condensation shell left in the loss can continue to be used as a crucible lining.
There are some challenges and opportunities in the smelting and casting process of titanium and titanium alloys. First of all, titanium has a high melting point, and the smelting process requires high-temperature conditions and high requirements for equipment and energy. Secondly, titanium metal easily reacts with oxygen, nitrogen and other elements in the molten state, resulting in an increase in impurity content and affecting product quality. Therefore, appropriate protective measures such as inert gas protection need to be taken. In addition, the smelting and casting process of titanium and titanium alloys also needs to consider the shape complexity, dimensional accuracy and surface quality requirements of the product.
However, with the continuous advancement of science and technology, the smelting and casting process of titanium and titanium alloys is also constantly developing. The introduction of new smelting equipment and technology has improved smelting efficiency and product quality. At the same time, the alloy design and modification technology of titanium alloys have further optimized the performance of titanium products. In addition, the smelting and casting process of titanium and titanium alloys is also very sustainable and environmentally friendly, and is in line with the development trend of modern industry.
In short, the smelting and casting process of titanium and titanium alloys plays an important role and has broad application prospects in modern industry. With the advancement of science and technology and the continuous improvement of processes, it is believed that the smelting and casting process of titanium and titanium alloys will play a more important role in future development.
