Processing methods of titanium alloy powder metallurgy

 

Date：[2024/8/2]
 

Titanium and its alloys are widely used in aerospace, military, and shipbuilding industries due to their low density, high specific strength, good biocompatibility, and stability at medium to high temperatures, as well as excellent mechanical properties and corrosion resistance. The traditional forging processing technology has advantages in preparing large-sized and simple shaped titanium profiles or products, but there are problems such as low yield, large resource waste, and high production costs in preparing complex structures and small and medium-sized titanium products. Powder near final forming technology can precisely compensate for this technical defect. Through the technical route of powder preparation and near final forming, titanium alloy products with various scales and structural characteristics can be manufactured in batches or customized. These small and medium-sized products have greater application potential and product added value in the fields of aerospace, military, medical, and civilian consumption, and are an important direction for promoting the low-carbon and green manufacturing transformation of the titanium industry in the future.

1. Pressing sintering

The United States has been researching the preparation of titanium alloy products by pressing and sintering titanium powder for a long time. Dynamet Technology has been committed to the production of titanium powder compression formed products, and some of its products have been applied on a small scale. The first powder metallurgy titanium product produced by the company was the Ti-6Al-4V alloy preform for the dome shell of Raytheon's Sidewinder missile. Later, powder metallurgy Ti-6Al-6V-2Sn alloy products were also produced for the Stinger missile warhead shell. Due to its significant contribution to titanium products, Dynamet Technology has become the sole supplier of powder titanium alloy products to Boeing. In addition, ADMA Products has been producing powder metallurgy titanium parts since 1985, with some products used in the aerospace industry. The Northwest Nonferrous Metals Research Institute in China has more than 30 years of experience in the research and development of titanium powder near net forming, and the developed porous titanium products have been applied in chemical, food and other fields.

2. Hot isostatic pressure

The hot isostatic pressing (HIP) process was invented by the Battelle Institute in the United States in the 1950s. This technology is a technique that uses inert gas as a pressure medium to compress and sinter products at a temperature of 850-2000 ℃ and a pressure of 100-200 MPa. It is currently the most important means of fully densifying powder formed titanium and titanium alloy structural components. The products have the characteristics of uniform structure, no texture, and no segregation.

The development of titanium alloy powder hot isostatic pressing technology abroad began in the 1850s. As early as the 1970s, the Russian Institute of Light Metals was the first in the world to develop a powder titanium alloy hydrogen pump turbine with a complex overall shape, which was applied in the RD-0120 hydrogen oxygen engine; The United States first achieved commercial applications in the aerospace field in the 1990s, and gradually expanded to the aviation and weapons fields, such as PW's F110 engine connecting rod, Tomahawk cruise missile F107 engine compressor rotor, Sidewind missile hood, F107 cruise missile engine impeller, and Stinger air defense missile warhead shell.

3. Powder injection molding

Metal Injection Molding (MIM) technology can directly prepare parts with or close to the final shape, avoiding or reducing machining and significantly reducing preparation costs. Therefore, powder injection molding technology is one of the most effective technical means for mass production of titanium and titanium alloy application components.

The 3C products in electronic communication, including mobile phones, smart wearables, eyeglass frames, and 5G signal components, are the most important application areas of powder injection molding technology, accounting for 84.2%. At present, iron-based materials are mainly used, and the lightweight design and pursuit of high quality of materials are the main directions for the future development of 3C products. Titanium alloys have the characteristics of low density (only half the density of iron-based materials), high strength, and corrosion resistance, which meet the requirements for lightweight and high-quality design of future materials. According to statistics, the market size of China's titanium injection molding industry reached 680 million yuan in 2020. Based on the demand side investment and supply side revenue growth, it is estimated that the market size will reach 2 billion yuan by 2026, with an annual growth rate of 20.13%.

Application of powder injection molded titanium alloy in consumer electronics: Huawei watch titanium alloy case, Apple phone titanium alloy frame

4. Additive Manufacturing

Additive Manufacturing (AM) is a forming technology that accumulates points, lines, and surfaces layer by layer. It is not affected by the complexity of the parts and can automatically, quickly, and accurately complete the design and manufacturing of complex parts. Compared with traditional manufacturing techniques, additive manufacturing has unique advantages in design freedom, complex part forming, and material utilization, making it a highly promising titanium alloy manufacturing technology. According to SmarTech analysis, the global metal 3D printing market reached $3.3 billion in 2019, including 3D printing equipment, materials, and services, and is expected to reach $11 billion by 2024, with titanium alloy being the most important printing metal.

Aerospace and military defense are the largest users of titanium additive manufacturing, which has been successfully used for direct forming of small precision components for aerospace engines and large complex components for aviation, such as key aerospace equipment components such as space launch systems, aircraft wings, integral control surfaces and doors, engine blades, etc.

Application of additive manufacturing titanium alloy in the aviation field: engine fuel injectors, military aircraft titanium alloy frames

As the basic raw material for the powder metallurgy near final forming process mentioned above, the cost and quality of powder are the most important factors affecting the price and performance of powder metallurgy products.
Shenzhen Yujiaxin Technology Co., Ltd. leads the future with innovative technology and independently develops titanium alloy metal injection molding processing technology. This process is exquisite and efficient, capable of accurately manufacturing complex medical device parts, medical implants, and key aerospace components. By precisely mixing titanium alloy powder and binder, injecting them into molds for molding, and then undergoing fine steps such as degreasing and sintering, the product ensures excellent biocompatibility, mechanical properties, and accuracy. Yujia Xin provides high-precision and high reliability component solutions for medical, aviation and other fields with excellent quality.