In order to reduce the price of titanium alloy materials, it is necessary to develop new low-cost alloy systems and improve production processes:
1. Reducing the cost of raw materials
Titanium has a high melting point, very active chemistry and strong chemical affinity with O, H, N and C, which makes it difficult to extract pure titanium. The Kroll magnesium reduction method is widely used in the industrial production of titanium sponge. The Kroll magnesium reduction process used for the production of titanium sponge is complex, with high energy consumption and long cycle times, and cannot be produced continuously. At the same time, a large amount of magnesium metal is required as a reducing agent, and the production cost is high. Currently, a breakthrough has been made in the direct electrochemical reduction process of TiO2 in molten CaCl2 developed by the University of Cambridge. The method produces titanium sponge with short production cycle and 40% lower production cost.
Most titanium alloys use high-value V as an alloying element to improve strength, and most of these alloying elements use Al-X as an intermediate alloy. Replacing V with cheap alloying elements such as Fe and Cr is an effective way to reduce the cost of titanium alloys. For example, Timet developed Ti-1.5Al-6.8Mo-4.5Fe and Ti-6Al-1.Fe-0.1Si.
With the advancement of titanium smelting technology, it is an effective way to reduce the cost of raw materials to use the residues and scrap produced during titanium production and processing as furnace charge after series of treatment to realise recycling production.
2. Reduce processing costs
Casting is a classic net (near) moulding process. The parts produced do not require machining or machining very little, thus saving a lot of metal. Casting can usually produce parts with complex shapes, but these parts are manufactured by other traditional processes, which are complex and costly to produce, especially titanium, which has a relatively high material price. Currently, titanium castings are widely used in the aerospace industry. In the automotive manufacturing industry, parts produced by casting methods include valves, turbochargers, etc. Powder metallurgy, as an advanced technology of modern metallurgy and material processing, plays an important role in the titanium industry. Titanium powder metallurgy near-forming technology can directly produce finished or near-finished size parts, reduce the consumption of raw materials, shorten the processing cycle, and save 20% to 50% of the cost compared with the traditional process. At present, the research of titanium powder metallurgy is in the stage of rapid development, mainly including several aspects: firstly, the preparation technology of high-quality and low-cost titanium powder and its industrialisation; secondly, the preparation technology of titanium powder metallurgy, which is also widely used in the automotive industry.
Laser forming technology (*** laser technology, CAD/CAM technology and materials technology combined with the new results) according to the computer model, *** with a complex shape of the end parts can be alloy powder once directly formed, the performance of the manufactured titanium parts between casting and forging.
3.Metal Powder Injection Moulding (MIM)
It is a fast-developing near (net) forming powder metallurgy technology, which can produce high-quality, high-precision complex parts. It is considered to be one of the favourable forming technologies currently available***.
Titanium coating technology is also a new technology that can reduce costs. For example: automotive brake pads with titanium coating on the surface; new γ-TiAl valves.
