TC4 Titanium Alloy Sheet Material From the Production Process to Reduce Costs

Ti-6Al-4V (TC4) titanium alloy is a typical α+β two-phase titanium alloy with excellent comprehensive properties. It is widely used in aviation, aerospace, ships, weapons, chemicals, medical treatment, sports and leisure and other fields .
More than 50% of the titanium alloys produced in the world are TC4 titanium alloys. In terms of industrial applications, TC4 titanium alloys account for more than 80%. TC4 titanium alloy has become the international universal titanium alloy with complete varieties and specifications and the largest industrial volume among all titanium alloy grades in the world. However, cost issues limit its wide application. Countries in the world, especially the United States, Japan, Russia, and China, are actively looking for methods and processes to reduce costs. The cost of CNC titanium machining  mainly depends on the cost of raw materials and the cost of smelting and processing. In order to reduce costs, on the one hand, cheap elements are used to reduce the cost of raw materials; on the other hand, the production process is improved to reduce smelting and processing costs.
At present, the Kroll method is used to refine titanium sponge in the world, and there is no feasible low-cost production method to replace this method. Therefore, before a major breakthrough in the production technology of sponge titanium, it is difficult to use only inexpensive alloying elements. The cost of titanium alloy is greatly reduced. However, in the titanium alloy production process, due to processing needs such as cutting head, trimming, surface turning and cleaning, a large amount of returned material will be generated. Because the cost of titanium alloy return material is only some additional costs caused by screening, crushing, and cleaning, it is less than one-third of the cost of sponge titanium. If the return material can be used in a large amount in the alloy preparation process, the cost can be significantly reduced. In the cost structure of titanium alloy sheets prepared by conventional production processes, the cost of sponge titanium accounts for about 40% of the total cost, and the cost of alloying elements only accounts for 6.7% of the total cost; the costs of smelting and deformation processing each account for about 20% and about 26% of the total cost. %. Therefore, reducing the cost of raw materials and shortening the processing flow are effective ways to reduce the cost of titanium alloys. In addition, the currently commonly used titanium alloy smelting process is vacuum consumable arc smelting (VAR), which requires pre-pressed electrodes. In order to ensure the strength of the electrode, the return material can only be added to the electrode in a small amount, the recycling rate is limited, and the cost reduction effect is limited. The increasing maturity of electron beam cooling bed smelting (EBCHM) technology provides an important technical approach for the low-cost preparation of titanium alloys.
EBCHM has the following advantages:
1) High and low-density inclusions can be eliminated well, and ingots with uniform structure can be obtained;
2) 100% of the return material can be used, while the VAR that produces Ti-6Al-4V alloy can only use less than 30% of the return material;
3) It can be smelted into ingots once;
4) Slabs can be produced, reducing the amount of subsequent processing. In this study, EBCHM was used to replace traditional VAR, and TC4 titanium alloy slabs were produced by adding a large amount of return material in a single smelting; the slabs were surface treated, coated and then directly billeted and rolled to prepare 8mm thick TC4 titanium alloy plates; at the same time, VAR Compared with the manufacturing cost of EBCHM ingots to prepare plates.