19‐1: Invited Paper: Development of INVAR alloy foil used in FMM.

According to different smelting processes, nonmetallic inclusions are divided into four grades: basic purity, industrial purity, high purity and ultra‐high purity to cope with the influence of inclusion size and quantity on INVAR foil. Smelting production was carried out according to different needs in OLED field. The concept of "extreme manufacturing" was inducted to design process. The "Four‐Ultra quality" controling that Ultra‐purity, Ultra‐smooth surface, Ultra‐flat shape and Ultra‐precise dimension were put forward and realized in the production process of INVAR alloy foil for FMM. The prepared INVAR alloy foil reached a high level and met the application requirements of FMM. [ABSTRACT FROM AUTHOR]