Research progress of atomisation and forming technology of high performance metallic materials

The research and development in liquid metal atomisation and forming technologies of high performance metallic materials with the emphases on gas atomised superalloy powders, spray formed superalloys, powder metallurgy TiAl alloys and spray formed high-speed steels at Beijing Institute of Aeronautical Materials are reviewed. The technology and equipment of argon atomisation and minus atmospheric pressure atomisation (i.e. atomisation in sub-atmospheric pressure atomising assembly) of superalloy powders were established. Major factors contributing to powder oxygen content, particle size and non-metallic inclusions have been identified. A variety of high-purity, fine-grained and high-quality spherical powders of superalloys were produced , which have been utilised in the research and production of hot section components, such as turbine disks in advanced aero-engines. Spray forming technologies of highly-alloyed materials were investigated and developed while taking the key technical issues for making sound performs into process consideration, such as formation and deposition of droplets, densification and shape control, and hot working of preforms. The relative densities of as-deposited performs of superalloys and high-speed steels could be higher than 99.0% after the optimisation of process parameters. Low cost and high performance spray formed superalloys and high-speed steels were developed. Spherical powders of TiAl alloys with high purity and low oxygen content were obtained using the argon atomization techniques, and high performance sheets were subsequently deformed.