Optimization of gas turbine blade heat treatment: application of thermal diffusion technology and high temperature shielding mud

As a modern key power mechanical equipment, gas turbine efficiency improvement is crucial to energy utilization and industrial development. In order to enhance the performance of gas turbines, researchers have taken various measures in the design and material selection of turbine blades. By optimizing blade design, selecting new high-temperature resistant materials, and coating the blade surface with high-temperature protective coatings (such as NiCoCrAlY coating), the working efficiency of gas turbines can be significantly improved. These coatings are favored by materials scientists because they are easy to implement, simple in principle, and effective.

However, gas turbine blades that operate for a long time in high-temperature environments face the problem of interdiffusion of elements between the coating and the substrate, which will seriously affect the coating performance. In order to solve this problem, surface heat treatment technology, such as applying high-temperature protective coatings and setting up diffusion barrier layers, can effectively improve the high-temperature resistance and service life of the blades, thereby improving the operating efficiency and reliability of the entire gas turbine.

Advantages of Heat Diffusion Technology and Shielding Slurry

Thermal diffusion technology has been used in high-temperature surface modification treatment since 1988. This technology can form a thin carbonized layer on the surface of carbon-containing materials such as steel, nickel alloy, diamond alloy and cemented carbide, significantly hardening the surface of the material being processed. Materials treated by thermal diffusion have higher hardness and excellent wear resistance and oxidation resistance, which can greatly increase the service life of rice metal stamping dies, forming tools, roll forming tools, etc., by up to 30 times.

In aero-engine manufacturing, the heat treatment process of turbine blades is crucial to improving engine performance. Dalian Yibang's newly introduced masking slurry is specially designed for high-temperature diffusion coating processes and can provide good protection in extreme environments exceeding 1000°C, thereby significantly improving production efficiency and process stability.

High temperature stability: Masking mud performs well in high temperature diffusion coating processes exceeding 1000°C, avoiding the risk of traditional masking materials softening at high temperatures and ensuring the reliability of the coating.

No nickel foil coating required: Compared with traditional methods, the masking mud does not require additional nickel foil coating, which simplifies the operation steps and saves labor time and material costs.

Fast curing: At room temperature, the masking mud begins to cure in just 15 minutes and is fully cured within 1 hour, significantly shortening the production cycle and making the dipping and brushing process more efficient.

Simple operation and easy removal: Operators can easily remove the solidified masking mud with a hard plastic knife, reducing the complexity of the process and the requirements for operating skills.

High work efficiency: The masking mud adopts the "dry powder + box" solution. One box can complete the masking work of about 10 parts, which significantly improves the efficiency and reliability of the process.

The application scenarios of heavy-duty gas turbines are mainly ground power supply, industrial and residential heating, so the final purpose of the turbine is reflected in the output power of the shaft, driving the generator to generate electricity, and a certain amount of exhaust temperature (for downstream waste heat boilers and steam turbines). When designing a gas turbine, it is necessary to take into account both single cycle and combined cycle. Gas turbines focus more on power generation efficiency and the finished product or cost-effectiveness of the product, and pursue durable and reliable materials, long maintenance cycles and long intervals. The design of aircraft engines focuses on thrust-to-weight ratio. The product should be designed to be as light and small as possible, and the thrust generated should be as large as possible. It is a single cycle, so the materials used are more "high-end". At the same time, when designing, more emphasis is placed on fuel economy under low-load operation. After all, aircraft spend most of their time in the stratosphere rather than taking off.

In fact, both aircraft engines and ground-based gas turbines are the jewels in the crown of industry due to the difficulty of manufacturing, long R&D cycle, and wide range of industries involved. However, they have different focuses and different challenges due to different application fields. There are very few companies or institutions in the world that can produce heavy-duty gas turbines and aircraft engines, such as GE Pratt & Whitney in the United States, Siemens in Germany, Rolls-Royce in the United Kingdom, Mitsubishi in Japan, etc., because it involves the intersection of many disciplines, system design, materials, processes, and manufacturing of key components, etc., with large investments, long time, and slow results. The above-mentioned companies have also experienced a long period of development to evolve and improve their products to the current level, with lower costs, higher performance and reliability, and lower emissions.