低温复杂结构件特种成形工艺

研究了等离子旋转电极制备低温钛合金球形粉末的特性,采用热等静压成形工艺,制备低温钛合金粉末冶金材料,并对比分析了组织与性能.以低碳钢为材质,加工装配专用芯模,开展粉末冶金TA7 ELI钛合金构件净成形技术研究,实现了大尺寸、薄壁、半封闭式火箭发动机低温转子高性能、高可靠性的整体净成形.结果表明:等离子旋转电极制备的低温钛合金球形粉末,具有非常高的球形度和振实密度,粒径分布可依据需求控制在一定范围内,非金属夹杂含量每千克不超过20个；粉末冶金低温钛合金材料性能全面达到同批次锻件性能水平,微观组织呈等轴状；粉末冶金低温钛合金氢泵叶轮已通过了发动机型号低温全程试车考核.

Special Forming Process of Cryogenic Complicated Structural Parts

Characters of spherical powders which were manufactured by plasma rotating electrode process(PREP) were investigated.Microstructure and performance of cryogenic titanium alloy which was manufactured by hot iso-static pressing(HIP) have been analyzed.Researches on powder metallurgy TA7ELI alloy near net-shape process with appropriative mold was made and assembled by mild steel has been developed,and the high performance and high dependability rotor with large dimension,thin-walled,semi-closed which was used for cryogenic rocket engine have been manufactured by near net-shape process technology.Cryogenic titanium alloy powders which were manufactured by PREP has very well sphericity shape,high tap-density,better granularity distribution,and nonmetallic impurity is lower than 20 per kilogram.Powder metallurgy titanium alloy has the same level performance with the forged material,and the microstructure of the powder metallurgy is equiaxial grain.Powder metallurgy cryogenic titanium alloy impeller which is used for hydrogen pump has past the engine test.