Prospects

1. Research on single crystal blades containing rhenium

In the composition design of single crystals, both alloy performance and process performance should be considered. Since single crystals do not have grain boundaries and are used in harsher environments, certain alloy elements with special effects are introduced. With the development of single crystal alloys, the chemical composition of alloys has the following changing trends: the introduction of Re elements, the introduction of platinum group elements such as Ru and Ir, and the increase of the content of refractory elements W, Mo, Re, and Ta; the total addition of refractory elements The amount of C, B, Hf and other elements is changed from 'complete removal' to 'limited use'; the content of Cr is reduced to allow more other alloying elements to be added to maintain the stability of the structure.

The rhenium-containing single crystal blade greatly improves its temperature resistance and creep strength. Compared with the first-generation single-crystal alloys, the second-generation single crystal alloys represented by PW’s PWA1484, RR’s CMSX-4, and GE’s Rene'N5 have appropriately increased cobalt by adding 3% rhenium. The content of molybdenum and molybdenum increases its working temperature by 30℃, and its endurance strength and oxidation and corrosion resistance have reached a good balance.

Single crystal blades containing rhenium are the future trend of aero-engine turbine blades. Because of its temperature resistance, creep strength, thermal fatigue strength, oxidation resistance and corrosion resistance, single crystal blades have been significantly improved compared with directionally solidified columnar alloys, and thus have quickly been universally recognized by the aviation gas turbine engine community. All advanced aeroengines use single crystal alloys as turbine blades.

2. Research on new superalloys

Market analysis New superalloys mainly include four types: powder superalloys, intermetallic compounds, ODS alloys and high-temperature metal self-lubricating materials:

Powder superalloy technology: FGH51 powder superalloy is a phase precipitation strengthened nickel-based superalloy prepared by powder metallurgy. The volume fraction of the γ phase of the alloy is about $,-, and the atomic fraction of its forming elements is about 50%. The manufacturing process of the alloy disc is to use vacuum induction melting to prepare the master alloy, and then atomize to prepare the pre-alloy powder, and then make the part blank. Compared with similar cast and forged superalloys, it has the advantages of uniform structure, fine grains, high yield and good fatigue performance. It is a superalloy with the highest strength level under current 650°C working conditions. This kind of high temperature gold is mainly used for the rotating parts of high-performance engines, such as turbine discs and bearing rings.

Intermetallic compounds are used to make components of various advanced vehicle power propulsion systems, reducing deadweight and improving efficiency;

ODS alloy has excellent high-temperature creep performance, high-temperature oxidation resistance, carbon and sulfur corrosion resistance. It can be used to manufacture key parts of engines, as well as thermal power generation systems, coal gasifiers, industrial gas turbines and industrial boilers, glass manufacturing, and automobiles. Diesel engines, nuclear reactors, etc.;

High-temperature metal-based self-lubricating materials are mainly used to produce high-temperature self-lubricating bearings, mainly used to replace oil-containing bearings, inlaid solid self-lubricating bearings, bimetallic bearings and cast-sulfur steel solid lubricating bearings (including cast steel surface vulcanized bearings) in metallurgy Application on equipment, the high temperature self-lubricating bearing has the advantages of high strength, large carrying capacity, good lubrication effect, reasonable structure design, low noise and long service life.