High-temperature alloys are a type of special alloy materials used in high-temperature environments and are widely used in aviation, aerospace, shipbuilding, petrochemical and other fields. High-temperature alloys have excellent high-temperature strength, high-temperature oxidation resistance, and high-temperature creep properties, and can maintain the mechanical properties and durability of materials in extreme high-temperature environments. The alloying elements in high-temperature alloys play a vital role. This article will introduce the main alloying elements related to g¢ or g¢¢ precipitation strengthening, including Al, Ti, Nb, Ta, Hf, etc.
Aluminum is one of the common alloying elements in high-temperature alloys. It is the basic component element forming the g¢-Ni3Al phase. When aluminum is added to high-temperature alloys, about 20% enters g solid solution and plays a solid solution strengthening role. And 80% aluminum forms Ni3Al with nickel for precipitation strengthening. The effect of aluminum on precipitation strengthening is first to form the g¢ phase, and as the aluminum content increases, the number of g¢ phases increases, thereby enhancing various strengthening mechanisms. Secondly, the addition of aluminum changes the solubility of each element in the g¢ phase. As the aluminum content increases, the amount of aluminum and nickel entering the g¢ phase increases, further increasing the amount of g¢ phase and increasing the strengthening effect. At the same time, the anti-phase domain boundary energy of g¢ is also changed, usually increasing the anti-phase domain boundary energy. The increase in the anti-phase domain boundary energy enhances the strengthening effect of the cutting mechanism. Third, the aluminum content increases, changing the mismatch between g¢ and g phases. Usually, increasing the absolute value of the mismatch degree causes the coherent strain field around the g¢ phase to be enhanced, thereby increasing the strengthening effect.
Research shows that aluminum content has a significant impact on the microstructure and mechanical properties of high-temperature alloys. Take GH2150 alloy as an example. GH2150 alloy is an Fe-based high-temperature alloy containing 3% W, 5% Mo and 1% Nb for solid solution strengthening, and containing 2% Ti and 0.56% to 1.84% aluminum for precipitation strengthening. As the aluminum content increases, the number of g¢ phases increases from 8.52% to 16.73%, the size change of g¢ slightly increases, and the g/g¢ mismatch degree e increases significantly, thus increasing the yield strength of GH2150 alloy at room temperature and 700°C. obviously increase. This shows that increasing the aluminum content can significantly improve the mechanical properties of superalloys.
In addition to aluminum, elements such as titanium, niobium, tantalum, and hafnium are also widely used in high-temperature alloys. Titanium is usually added together with aluminum, which can form the L12 structure Ti3Al phase at high temperatures, further enhancing the strength and stability of the alloy. Niobium and tantalum can form a high-density g¢¢ phase, further improving the high-temperature strength and oxidation resistance of the alloy. Hafnium can promote the mutual transformation between g phase and g¢ phase, thereby enhancing the strength and stability of the alloy.
In addition to the above elements, there are other elements that are also widely used in high-temperature alloys, such as tungsten, molybdenum, iron, etc. These elements can work together with aluminum, titanium, niobium, tantalum, hafnium and other elements to form a more complex alloy system, further improving the performance and stability of high-temperature alloys.
In summary, alloying elements play an important role in high-temperature alloys and can improve the mechanical properties, oxidation resistance and creep properties of the alloy through mechanisms such as solid solution strengthening and precipitation strengthening. Different alloying elements can interact with each other to form more complex alloy systems, thereby improving the performance and stability of high-temperature alloys. Therefore, reasonable design and selection of alloy elements are of great significance for the development and application of high-temperature alloys.
In short, high-temperature alloys, as important special alloy materials, have been widely used in aviation, aerospace, shipbuilding, petrochemical and other fields. As an important component of high-temperature alloys, alloying elements play a vital role in the performance and stability of high-temperature alloys. Therefore, in the development and application of high-temperature alloys, it is necessary to give full play to the role of alloy elements. Through reasonable design and selection of alloy elements, the performance and stability of high-temperature alloys can be improved to meet the needs of use in various high-temperature environments.
Tianjin Anton Metal Manufacture Co., Ltd. is a company specializing in the production of various nickel-based alloys, Hastelloy alloys and high-temperature alloy materials. The company was established in 1989 with a registered capital of 10.0 million, specializing in the production and sales of alloy materials. Anton Metal’s products are widely used in aerospace, chemical industry, electric power, automobile, nuclear energy and other fields, and can also provide customized alloy material solutions according to customer needs. If you need to know the price consultation of alloy materials or provide customized alloy material solutions, please feel free to contact the sales staff.
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Post time: Oct-21-2023
