The British aero-engine giant Rolls · Royce has been focusing on the design and manufacturing technology of wall cooling and laminated single crystal blades at the hot end of the engine with high thrust/weight ratio. In the 1990s, it has successively completed the design, materials and manufacturing technology of the high-efficiency air-cooled blade cooling system, and passed the life cycle assessment of the engine.
Howmet Company of the United States and Rolls · Royce Company have carried out a lot of research work on the material system and process technology of dual-performance integral bladed disc. At the end of the 20th century, they developed mature and complete supporting investment casting technology and related process equipment, and successfully manufactured the integral bladed disc matched with the oriented columnar blade and equiaxed crystal disk. The service life of the matched engine has been increased by 2-3 times, and the output power has been increased by 7.3%~9.2%.
Allision produced high cooling efficiency single crystal laminate alloy turbine blades in the late 1990s, and manufactured ultra-gas-cooled single crystal blades with the help of casting cooling technology. With the help of soluble core technology and investment casting technology, the Russian Saturn Scientific Research and Production Consortium has realized the mass production of high-efficiency air-cooled single crystal hollow blades, which has been successfully applied to the AL – 31FN engine (see figure).
At the end of the 20th century, Carret and PCC broke through the “metallurgy – grain – structure” in-situ composite control technology of large thin-walled complex superalloy investment castings. The maximum forming size of the engine casing investment castings manufactured by this technology is 1027mm, the wall thickness can reach 0.8~1.2mm, the grain size can be controlled in 1.0~5.0mm, and the material utilization rate has increased by more than 50%.
At present, foreign countries have formed new technologies for manufacturing super air-cooled hollow blades, such as porous laminates alloy parts, precision cast single crystal blades of porous laminates alloy, super air-cooled hollow blades, micro laminated composite blades, and corresponding divergent cooling (Lamilloy), cast cooling (Cast Cool), super cooling (Super Cooling).