Cobalt Chrome Alloy Casting superalloy is a type of sup […]
Cobalt Chrome Alloy Casting superalloy is a type of superalloy that can or can only be formed by casting methods. Its main features are:
1. Has a wider composition range
Since it is not necessary to take into account its deformation processing performance, alloy design can focus on optimizing its performance. For nickel-based superalloys, the γ 'content of 60% or more can be adjusted by adjusting the composition so that the alloy retains excellent properties up to 85% of its melting point.
2 has a broader application areas
Due to the special advantages of the casting method, high-temperature alloy castings of any complexity and shape can be designed and manufactured according to the requirements of the parts.
According to the casting alloy temperature, can be divided into the following three categories:
The first category: at -253 ~ 650 ℃ using the equiaxed casting high-temperature alloy
Such alloys have good overall properties over a wide range of temperatures, especially at low temperatures without losing strength and ductility. For example, in K4169 alloy with larger amount on aviation and space engines, the tensile strength at 650 ℃ is 1000MPa, the yield strength is 850MPa and the tensile plasticity is 15%. The durable life under 650 ℃ and 620MPa stress is 200 hours. Has been used to make aero-engine diffuser casings and aerospace engines in a variety of pump with complex structures and so on.
The second category: at 650 ~ 950 ℃ used equiaxed casting high temperature alloys
Such alloys have high mechanical properties at high temperature and hot corrosion resistance. For example, K419 alloy, 950 ℃, tensile strength greater than 700MPa, tensile ductility greater than 6%; 950 ℃, 200 hours lasting strength limit greater than 230MPa. Such alloys are suitable for use as aeroengine turbine blades, guide vanes and casting turbine.
The third category: at 950 ~ 1100 ℃ using the directional solidification columnar crystal and single crystal superalloy
Such alloys in this temperature range has excellent overall performance and oxidation resistance, hot corrosion resistance. For example DD402 single crystal alloy, 1100 ℃, 130MPa stress life expectancy greater than 100 hours. This is the highest temperature turbine blade material in China and is suitable for the production of a first-class turbine blade for a new high-performance engine.
With the continuous improvement of precision casting technology, new special techniques are also emerging. Fine-grain casting technology, directional solidification technology, CA technology of complex thin-walled structural parts and so on have greatly raised the level of foundry superalloy, the application range continues to increase.