Type Of Alloy Strengthening

According to the type of alloy strengthening, high-temperature alloys can be divided into solid solution strengthening high-temperature alloys and aging precipitation strengthening alloys.
(1) Solid solution strengthening type
The so-called solid solution strengthening type is to add some alloy elements to iron, nickel or cobalt base superalloys to form single-phase austenite structure. The solute atoms distort the matrix lattice of solid solution and strengthen the sliding resistance in solid solution. Some solute atoms can reduce the stacking fault energy of the alloy system, increase the tendency of dislocation decomposition, and make it difficult to carry out cross slip. The alloy is strengthened, achieving the goal of high-temperature alloy strengthening.
⑵ Aging precipitation strengthening
The so-called aging precipitation strengthening refers to a heat treatment process in which alloy workpieces undergo solid solution treatment, cold plastic deformation, and are placed at a higher temperature or room temperature to maintain their properties. For example, GH4169 alloy has a maximum yield strength of 1000 MPa at 650 ℃, and the alloy temperature for making blades can reach 950 ℃.
3. Material forming method
By material forming methods, it can be divided into: cast high-temperature alloys (including ordinary cast alloys, single crystal alloys, directional alloys, etc.), deformed high-temperature alloys, and powder metallurgy high-temperature alloys (including ordinary powder metallurgy and oxide dispersion strengthened high-temperature alloys).
(1) Cast high-temperature alloy
The alloy material used to directly prepare components by casting method is called casting high-temperature alloy. According to the composition of the alloy matrix, it can be divided into three types: iron based cast high-temperature alloys, nickel based cast high-temperature alloys, and cobalt based cast high-temperature alloys. According to the crystallization mode, it can be divided into four types: polycrystalline casting superalloy, Directional solidification casting superalloy, directional eutectic casting superalloy and single crystal casting superalloy.
⑵ Deformed high-temperature alloy
It is still the most commonly used material in aviation engines and is widely used both domestically and internationally. The annual production of deformed high-temperature alloys in China is about 1/8 of that in the United States [2]. Taking GH4169 alloy as an example, it is one of the most widely used major varieties both domestically and internationally. China mainly uses bolts, compressors, wheels, and oil throwers as the main components of turboshaft engines. With the increasing maturity of other alloy products, the use of deformed high-temperature alloys may gradually decrease, but they will still dominate in the coming decades.